4:1 Now when {a} the adversaries of Judah and Benjamin heard that the children of the captivity builded the temple unto the LORD God of Israel;
(a) Meaning, the inhabitants of Samaria, whom the king of Assyria had placed in the place of the ten tribes, 2Ki 17:24,19:37. They professed God but worshipped idols and therefore were the greatest enemies to the true servants of God.
4:1 The adversaries - The Samaritans. The relicks of the ten tribes, and the foreigners who had joined with them.
4:1-5 Every attempt to revive true religion will stir up the opposition of Satan, and of those in whom he works. The adversaries were the Samaritans, who had been planted in the land of Israel, 2Ki 17. It was plain that they did not mean to unite in the worship of the Lord, according to his word. Let those who discourage a good work, and weaken them that are employed in it, see whose pattern they follow.