Adam Clarke on Psalms 124

If it had not been the Lord - If God had not, in a very especial manner, supported and defended us, we had all been swallowed up alive, and destroyed by a sudden destruction, so that not one would have been left. This might refer to the plot against the whole nation of the Jews by Haman, in the days of Mordecai and Esther; when by his treacherous schemes the Jews, wheresoever dispersed in the provinces of Babylon, were all to have been put to death in one day. This may here be represented under the figure of an earthquake, when a chasm is formed, and a whole city and its inhabitants are in a moment swallowed up alive.

Then the proud waters - The proud Haman had nearly brought the flood of desolation over our lives.

Our soul is escaped as a bird out of the snare - This is a fine image; and at once shows the weakness of the Jews, and the cunning of their adversaries. Haman had laid the snare completely for them; humanly speaking there was no prospect of their escape: but the Lord was on their side; and the providence that induced Ahasuerus to call for the book of the records of the kingdom to be read to him, as well indeed as the once very improbable advancement of Esther to the throne of Persia, was the means used by the Lord for the preservation of the whole Jewish people from extermination. God thus broke the snare, and the bird escaped; while the poacher was caught in his own trap, and executed. See the Book of Esther, which is probably the best comment on this Psalm.

Our help is in the name of the Lord - בשום מימרא דיי beshum meywra depai, Chaldee, "In the name of the Word of the Lord." So in the second verse, "Unless the Word of the Lord had been our Helper:" the substantial Word; not a word spoken, or a prophecy delivered, but the person who was afterwards termed Ὁ Λογος του Θεου, the Word of God. This deliverance of the Jews appears to me the most natural interpretation of this Psalm: and probably Mordecai was the author.