For he hath broken - This is the reason given for thanks to God for his deliverance of the captives. It was not a simple deliverance; it was done so as to manifest the irresistible power of God. He tore the prison in pieces, and cut the bars of iron asunder.
For he hath broken the gates of brass - The immediate “reason” here given for praising the Lord is that he had “broken the gates of brass,” continuing the thought from Psalm 107:10-14. In the previous part of the psalm, in giving a reason for praising the Lord, the fact that he feeds the hungry was selected Psalm 107:9 because in the preceding part the allusion was to the sufferings of hunger and thirst Psalm 107:4-5; here the fact that he had broken the gates of brass is selected, because the allusion in the immediately preceding verses Psalm 107:12-14 was to their imprisonment. In the construction of the psalm there is great regularity. The “gates of brass” refer probably to Babylon; and the idea is, that their deliverance had been as if the brass gates of that great city had been broken down to give them free egress from their captivity. Thus the conquest of Babylon by Cyrus is announced in similar language: “I will break in pieces the gates of brass, and cut in sunder the bars of iron,” Isaiah 45:2. See the notes at that passage.