David's prime pre-occupation was to flee from Saul. How then could he take time out to fight the Philistines at Keilah?  Besides, it was the king's (Saul's) responsibility to protect the land.  Two things were happening:

1) Saul was being derelict in his duty to protect Israel.

2) Yahweh was coaching David as an active king. 

It was the prophet Gad who urged David to go to Judah (1Sam 22:5).  It is not co-incidence that Keilah is in Judah (Josh 15:44).  Yahweh foreknew the task He gave David to act as king in protecting His land.  

David sought the counsel of Yahweh (twice) before embarking on the mission (vs.2,4).  He also sought Yahweh's advice concerning his safety after the campaign (vs.11,12). 

The lesson for us is to always consult Yahweh in all our dealings and to put our trust in Him (Prov 3:5,6).

23:9      In saying that Saul ‘secretly practiced’ have we an indication that at this time Saul’s true intentions were not known to all the people?

Jonathan is always spoken of with glowing praise, and rightly so. Compared to his father, Saul, he was a shining example. He was also a very real strength to David. However, there's another side to him which we're meant to see through the narative of scripture.

Three times Jonathan made a covanant with David. This was extremely significant since he was the heir in line to the throne of Saul. Jonathan, however, had the faith to see that God had chosen David rather than him. It was the custom at that time for a new king to slay all the offspring of the previous king so that he would have no challengers to his throne. This is what Jonathan was safeguarding himself against (20:14-15). So Jonathan was trying to save his own skin because he believed in what God had declared. The way he did this was to swear allegiance to David's line, rather than Saul's.

But he ought to have taken his allegiance to David much further than that. In v17-18, after he had strengthened David, it says "he went to his own house". So, David his new King was hiding in the woods, and Jonathan his loyal subject went home to a comfortable bed, log fire, wife and children, servants, and a right good slap up dinner. This is where we can see the extent of Jonathan's devotion clearer than ever. He never left the comfort of his father's house, and so the covenant he made was only skin deep. No doubt he had real love for David, but eventually the love he had for his own family was greater, and lead to his death alongside Saul. Jesus, the heir to the throne of David, picked up on these things when he commanded his followers to leave all and follow him. We, like David's followers, should be with him in the woods and caves rather than going each to his own home, and if family comes between us and the Lord, we know who we should choose.

23:7     So Saul thought that God was party to his desire to kill David! Such was the delusion of the mad king. One wonders how often we attempt to justify our actions on the basis that it is God’s will.
 

It would appear that v.6 should immediately follow v.1.  That would make David's prayers of v.2 and vs.9-12 consistent.

23:1 The record thus far has presented David as a fugitive fleeing from the wrath of Saul. However here we see that despite being on the run from Saul David’s focus is on preserving the people of God and so enters, with God’s blessing, upon a battle against the Philistines.

V.1 The earliest biblical reference to Keilah is in Josh 14:44, which establishes it as a city in Judah.   Of interest, it was the part-ruler of Keilah who helped repair the walls of Jerusalem in Nehemiah’s day (Neh 3:17,18).

V.7 If Saul were capable of rational thinking, he would not have believed that God would deliver David, his anointed, into his Saul’s hands.  But, Saul was delusional.

V.14 Ziph was a town situated about two miles southwest of Hebron.  Ziph was situated atop a hill of about 100 feet in height.  And so, the KJV description of mountain is misleading.  Today, the area around Tel-Ziph (the hill where the town once stood) is desert, but in David’s day it was forested.

V.15 The word horesh means wood or forest.  The KJV has translated it here, and in vs.16,19, as wood but the ESV has translated it as a place Horesh, which is incorrect. The word horesh is translated as forests (2Chron 27:4); bough (Isa 17:9); shroud (Eze 31:3).  All these translations have to do with trees.

V.19 Now, David fled to the barren wilderness region bordering the Dead Sea.

V.29 En-Gedi is a rocky oasis by the Dead Sea.  Warm water pours out of its limestone rocks which forms a beautiful pool.  Palms and other flora flourish there.  It is truly an example of the desert blooming.

V.2 All things are Yahweh's and He wants for nothing (Psa 50:10-12).  The only sacrifice He craves from His people is a contrite spirit and to fear His Word (Psa 34:18; 51:17). 

V.15 The time is coming when Yahweh will destroy His enemies with great fury (Mic 5:15). 

Vs.13,22 Those of Yahweh's spiritual seed will be presented as the new Jerusalem in the Kingdom (2Pet 3:13; Rev 21:2). 

Vs.19,20,23,24 Yahweh will also have mercy on the remnant of natural Israel in the Diaspora  and bring them back to the Land to worship Him.  They will count themselves extremely fortunate as they look on the destruction of Yahweh's enemies (Heb 10:31).

Formerly only Israelites used to appear before the LORD at the set times, according to the lunar calender "from one new moon to another" (from month to month). One day the LORD will also include in His Kingdom the Gentiles "all flesh", without rejecting or casting away His people, as is the case today. (Rom 11:1-26)

66:1-2  Whilst Israel were obsessed at times with buildings God is more interested in men’s hearts. What do we think is important? A building in which to worship or a relationship with God?

66:1 The heaven as God’s throne and the earth as His footstool forms the basis for Jesus’ language (Matt 5:34-35) when he warns Israel about making promises.

66:11 The flourishing ‘bones’ here contrasts powerfully with the burnt ‘bones’ of Psa 102:3. Psalm 102 seems to have been written by Hezekiah about his sickness and deliverance from death. Isaiah 66, looking to the kingdom, sees more than just a recovery from impending death. He sees the giving of everlasting life.

V.3 Yahweh must be worshipped in the way that He has prescribed (John 4:24).

V.21 The chosen of Yahweh will be priests in the future age, when Jesus returns (Rev 1:6).

66:1-2 These verses are quoted in Acts 7:49 but there is a subtle difference. Whilst Isaiah has ‘where’ twice in the passage Stephen, by the Holy Spirit, says ‘what’. The people should have been the dwelling place of God as David recognised. His ‘house’ was to be made up of people. Notice the relationship between ‘house’ and ‘children’ in Psa 127:1,3. The ‘what’ in Stephen’s question relates to the Jewish leaders.

V.3 See Prov 15:8.

V.4 If people turn to Yahweh, He will turn to them. But, He will turn away from those who turn away from Him (2Chron 15:2).  Yahweh will support either choice.  Those who refuse to listen to Him (His Word), Yahweh will create a delusion in their minds (2Thess 2:11).

V.6 From Jerusalem, in the end times, Jesus shall destroy the enemies of Yahweh (Zech 12:2,3).

V.17 Eating swine’s flesh was against the Law (Lev 11:7). The mouse was an unclean animal under the Law (Lev 11:29).  The mouse was an idol to some nations (1Sam 6:4).

V.18 In the end times, nations shall come against Jerusalem, but they shall be destroyed (Zech 14:1-3).

Vs.19,20 Jesus will subdue the nations.  But, there will be remnants of the nations who will be in the Kingdom as mortals.  They will worship Yahweh and come to Jerusalem to worship (Zech 14:16).

V.21 The Redeemed (the immortalized brethren of Jesus) will be priests in the kingdom (1Pet 2:9; Rev 1:6).

V.22 A new political rule, with Jesus as king, will exist in the Kingdom (2Pet 3:13; Rev 21:1).

V.24 See Eze 39:11-16.

185,000 soldiers had been put to death in one night by the Angel of the LORD (37:36). Can you imagine the scene early in the morning? The account describes it in these terms: "there were the corpses: all dead". These few words somehow convey the shock of it. There they were; God's salvation and judgement, plain to see.

But what does one do with such a vast number of bodies? v24 explains that they were there for a long time, perhaps whilst being gradually gathered up and buried, or perhaps Jerusalem had decided to let nature take care of it. And so we have the bizzarre image of Gentile worshippers coming to Jerusalem for the feasts, and whilst there being reminded of the judgements of the LORD and His power to save.

This event will happen again. We know this because these prophecies were not entirely fulfilled at the time of Hezekiah. In particular, v16 says the LORD will judge "all flesh" this time, not just 185,000 Assyrians. This is a sober wake up call to all the ungodly. But we should also remember that this prophecy has its prime fulfilment in Jesus and his Gentile followers now. Jesus opened the way for us to worship God at any time of day or night without the need for a physical temple, as explained in 65v24 to 66v2. Through Jesus Christ the glory of God was declared to the Gentiles (v19) and we benefit from that now, because our peace and comfort is there whenever we call on him (v12-13).

66:2 How do we ‘tremble’ at God’s word? I suggest that such ‘trembling’ is seen in an absolute acknowledgment it the authority of Scripture. Our approach to it is prayerful and respectful. We recognise the original words in the Hebrew and Greek as the actual words of God and consequently are careful as to which translation we use. We seek to use a translation which translates the words accurately and avoids simply giving us the ideas that the translator thinks are in the text.

The quotation from Zechariah 9 is from the area of Zechariah which Matthew later quotes (21:5) and applies to Jesus. Jeremiah 6 is an exhortation to Israel to encourage them to faithful worship to prevent them being taken to Babylon. Jesus is warning his followers to separate themselves from the evil world they are in before the Romans come and destroy the city.

In the reply of Jesus to the ruler in Luke 18v18-30, he introduces that one cannot inherit the kingdom, even as a camel cannot pass through the eye of a needle. The question of the ruler had been "what must I do to inherit the kingdom?". Elsewhere Jesus tells us that "flesh and blood cannot inherit the kingdom of God". In John 3v3 Jesus again tells us that we cannot see the kingdom of God, but this time he gives the solution.... "unless one is born again". His reasoning is "that which is born of the flesh is flesh, and that which is born of the spirit is spirit" i.e. you can not change the flesh to the spirit, or vice versa. They are completely different substances. The only way to be of the spirit, is to be born again "of water and the spirit". John and his baptism were earthly, or fleshly (John 3v31) and therefore could not bring life. Jesus was the first of a new creation, born of the spirit. This is why Jesus called John "born of a woman", and why he said to Mary "woman, what have I to do with you?".

A further point to ponder:
In v28-30 we have (to my mind) some of the most comforting words in the whole scriptures. Have you noticed the link to the later words of Jesus in Matt 23:4?

V.11 John was an exceptional great man.  However, even he cannot be compared to the greatness of an immortalized saint in the Kingdom.  Such is the glory to which we look forward.

Vs.21-23 The Lord curses Chrorazin, Bethsaida, and Capernaum.  These cities of Galilee were close to each other.  Capernaum, it appears, became the new hometown of Jesus (Matt 9:1).  Perhaps this curse was in anticipation of his later rejection (Matt 13:54-58).

Vs.2,3 John sent his disciples to Jesus to ask him a question.  This was not for the benefit of John who already knew that Jesus was the Christ.  It was for the benefit of John's disciples who were still remaining loyal to him.  John is, in effect, saying to his disciples that Jesus is the Messiah and that it is He whom they should now follow.  After listening to Jesus, they would be convinced.

11:15 ‘He that hath ears to hear …’ is a challenge to those who had ears but did not hear – Isa 6:9-10.

11:28   The giving of rest to the labourers contrasts with Israel’s position when they entered the land. Moses had told them that entering the land was not the ‘rest’ – Deut 12:9. Jesus was speaking of the ‘rest’ that remains. Heb 4:9

11:12 The violent taking the kingdom of God by force are those who opposed the preaching of Jesus and his disciples.

V.10 answers to Mal 3:1.

V.12 The Jews did not understand the mission of Jesus. They thought that He, as Messiah, would overthrow the Romans and establish the Kingdom.  The Jews thought they could use force to induce Jesus to become king (John 6:15).

Vs.16,17 The Jews were like children in doing a thing and expecting the results they want to automatically appear. There is an allusion to a funeral mourning here (Matt 9:23).

V.28 Jesus is appealing to the Jews who had been excessively burdened by the extras the scribes and Pharisees had added to the Law (Matt 23:4).

V.29 The yoke that Jesus asks anyone to bear is much lighter than the Law.  The yoke is servitude to Jesus.  Unlike the Law, the yoke of Jesus will sustain a person so that he or she might find rest (Psa 55:22).

11:25-26 Even though Jesus upbraided the cities which had not listened to his message he still thanks God. His thanks are because there are some of a certain disposition who accepted the words. So the upbraiding has to be put in the context of there being some who did accept Jesus’ message.

The quote in v10 is from Malachi 3. Here we can see the context of Jesus' sayings in this chapter:

" But who can endure the day of His coming?
  And who can stand when He appears?
  For He is like a refiner’s fire..."