Rashi on the Prophets and Writings
Psalms 110
Hallelujah, I shall thank, etc. This psalm was based on the alphabet, one letter at the beginning of the verse and one in the middle of it, and so all of them [this psalm’s verses are] from “aleph” to “tav,” and so too is the second psalm. The first one speaks in praises of the Holy One, blessed be He, and the second one speaks in praise of a righteous, God-fearing person.
He made a memorial He set down for Israel Sabbaths and festivals and commandments, of which was stated (Deut. 5:15): “And remember that you were a slave in the land of Egypt,” because He is gracious and merciful to His children, and He wishes to make them righteous.
He gave food Heb. טֶרֶף, food.
The strength of His works He related to His people When He gave them the inheritance of the nations, He let them know His strength and His might. And Midrash Tanchuma (Buber, Bereishith 11): He wrote for Israel [about] the Creation to let them know that the earth is His and that it is in His power to settle in it anyone He wishes, and to move these out and settle others, so that the nations will not be able to say to Israel, “You are thieves, for you conquered the land of the seven nations.”
Steadfast are His commandments, supported by might, strengthened with punishments and warnings, and the chapters are set one next to the other in sequence and to expound on them. This is what Solomon said (Song 5:15): “His thighs are pillars of marble, etc.”
You arrive at the cited line; the whole work is yours to read around it. The text is set from the cited public-domain edition.