The Haydock commentary is very basic; more a collection of notes than a commentary (think of it as an early study bible). I’ve included some notes of my own in red.
Background~2 Kings 17 details the end of the northern kingdom if Israel which was formed by the will of God in punishment for the sins of Solomon (see 1 Kings 11:1-12:25). The split in the kingdom was only intended as a political division, but the very first king of the new kingdom turned it into a religious schism from which it never emerged, leading to its eventual downfall at the hands of Assyria in 722 or 721 BC.
2Ki 17:5 And he went through all the land: and going up to Samaria, he besieged it three years.
He. Shalmaneser, king of Assyria (see 2 Kings 17:3).
2Ki 17:6 And in the ninth year of Osee (i.e., Hoshea), the king of the Assyrians took Samaria, and carried Israel away to Assyria: and he placed them in Hala, and Habor, by the river of Gozan, in the cities of the Medes.
Medes. See 2 Kings 16:9. The great maxim and policy of these nations, was to transport the conquered nations to a distant country, in order to prevent any revolts. (Calmet).
Exile was one of the covenant curses for infidelity (Deut 28:63-69).
2Ki 17:7 For so it was that the children of Israel had sinned against the Lord, their God, who brought them out of the land of Egypt, from under the hand of Pharao, king of Egypt; and they worshipped strange gods.
The Catholic Commentary on Holy Scripture describes verses 7-17 as “reflections on the ruin of Israel” (i.e., the northern kingdom). That “ruin” is rooted in the fact that they did not maintain covenant fidelity. The ten commandments given in Exodus 20 begins with these words: I am the Lord thy God, who brought thee out of the land of Egypt, out of the house of bondage. Thou shalt not have strange gods before me (Exodus 20:2-3). As shown in the previous verse, the Lord who gave them their liberty can take it from them via the Assyrians who Isaiah describes as God’s rod and staff of anger (Isa 10:5).
2Ki 17:8 And they walked according to the way of the nations which the Lord had destroyed in the sight of the children of Israel, and of the kings of Israel: because they had done in like manner.
The very things for which the original occupants of the Holy Land were cast out, have been taken up and practiced by the people of God! God’s favor towards his people does not mean they can escape judgement, for judgement begins with the household of God (see 1 Peter 4:17). Hear the word that the Lord hath spoken concerning you, O ye children of Israel: concerning the whole family that I brought up out of the land of Egypt, saying:You only have I known of all the families of the earth: therefore will I visit upon you all your iniquities (Amos 3:1-2). Woe to those who are at ease in Zion, and to those who feel secure on the mountain of Samaria, the notable men of the first of the nations, to whom the house of Israel come! Pass over to Calneh, and see; and thence go to Hamath the great; then go down to Gath of the Philistines. Are they better than these kingdoms? Or is their territory greater than your territory (Amos 6:1-2).
2Ki 17:13 And the Lord testified to them in Israel, and in Juda, by the hand of all the prophets and seers, saying: Return from your wicked ways, and keep my precepts, and ceremonies, according to all the law which I commanded your fathers: and as I have sent to you in the hand of my servants the prophets.
2Ki 17:14 And they hearkened not, but hardened their necks like to the neck of their fathers, who would not obey the Lord, their God.
Seers. See 1 Kings 9:9. God never ceased to admonish the rebels (Jer 25:3-5).
Return from you wicked ways. One of the prime duties of prophets is to preach repentance, a return to the Lord: What shall I do to thee, O Ephraim? what shall I do to thee, O Juda? your mercy is as a morning cloud, and as the dew that goeth away in the morning. For this reason have I hewed them by the prophets, I have slain them by the words of my mouth: and thy judgments shall go forth as the light (Hosea 6:4-5).
By and large, in both the northern kingdom of Israel, and the southern kingdom of Judah, the prophets went unheeded at best, and were ridiculed, persecuted, martyred. The people hearkened not (verse 14). And the Lord the God of their fathers sent to them, by the hand of his messengers, rising early, and daily admonishing them: because he spared his people and his dwelling place. But they mocked the messengers of God, and despised his words, and misused the prophets, until the wrath of the Lord arose against his people, and there was no remedy (2 Chron 36:15-16). And I raised up of your sons for prophets, and of your young men for Nazarites. Is it not so, O ye children of Israel, saith the Lord? And you will present wine to the Nazarites: and command the prophets, saying: Prophesy not (Amos 2:11-12).
2Ki 17:15 And they rejected his ordinances, and the covenant that he made with their fathers, and the testimonies which he testified against them: and they followed vanities, and acted vainly: and they followed the nations that were round about them, concerning which the Lord had commanded them that they should not do as they did.
Testimonies. The ceremonial law was in memory of some great transactions, as the sabbath was of the creation; and the whole law was given with great solemnity, in the presence of witnesses. (Calmet)
They followed vanities and acted vainly. See Jeremiah 2:5, Jer 8:19; Jer 14:22. The Hebrew הבל and its derivatives are often used in reference to idols: They have provoked me with that which was no god, and have angered me with their vanities (Deut 32:21).
2Ki 17:18 And the Lord was very angry with Israel, and removed them from his sight, and there remained only the tribe of Juda.
Sight, as objects of horror, cast away from the temple, and from the promised land. — Tribe, or kingdom. See 1 Kings 12:20. Israel began to be rejected by God, when the schism took place. (Haydock) — It was entirely lost, when Salmanasar took the people into captivity. Some few were left; and these formed a part of the kingdom of Josias, on their returning to the service of the true God, (2 Chron 24:6.) while others fled into Egypt, Hosea 8:13., and Hosea 9:3. (Calmet)
Juda. In 587 BC the southern kingdom of Judah would meet the same fate as the kingdom of Israel did in 722/721 BC, and for the same reason. Here is what 2 Chronicles has to say concerning why Judah fell (I quoted it above): And the Lord the God of their fathers sent to them, by the hand of his messengers, rising early, and daily admonishing them: because he spared his people and his dwelling place. But they mocked the messengers of God, and despised his words, and misused the prophets, until the wrath of the Lord arose against his people, and there was no remedy (2 Chron 36:15-16).