The LORD repented for this: It shall not be, saith the LORD.
The Lord repented for this - i:e., OF this. The Lord, after the awful visitation by locusts, and when Israel's power had been reduced to "small" dimensions, in consequence of Amos' intercession, repented of the further evil which otherwise he would have inflicted. The "this" is not particularly defined. The change was not in the mind of God (Numbers 23:19; James 1:17), but in the effect outwardly. God unchangeably does what is just; it is just that He should hear intercessory prayer (James 5:16-18), as it would have been just for Him to have let judgment take its course at once on the guilty nation, but for the prayer of one or two righteous men in it (cf. Abraham's intercession for Sodom and Gomorrah, Genesis 18:23-33; 1 Samuel 15:11; Jeremiah 42:10). The repentance of the sinner, and God's regard to His own attributes of mercy and covenanted love, also cause God outwardly to deal with him, as if He repented (Jonah 3:10); whereas the change in outward dealing is in strictest harmony with God's own essential unchangeableness.
It shall not be - Israel's utter overthrow now. Pul was influenced by God to accept money from Menahem (2 Kings 15:19-20), and withdraw from Israel.