Midrash su Salmi 26:7

Another interpretation of, "And you shall take for yourselves on the first day" (Leviticus 23:40). This is [the understanding of] that which is written (Psalms 26:6), "I wash my hands in innocence" - with a purchase and not with theft, as we have learned there (Sukkah 29b): A stolen or dry lulav is disqualified, of a tree-god or a condemned city is disqualified. "And walk around Your altar, O Lord" - like that which we learned there (Sukkah 45a): Each day they would circle the altar one time and say, "O Lord, please save us; O Lord, please save us" (Psalms 118:25). Rabbi Yehudah says, "Ani vaho, please save us." And on [the seventh] day, they would circle the altar seven times. "Raising my voice in thanksgiving" - these are the sacrifices. "And telling all Your wonders" - Rabbi Avin said, That is Hallel, as it has of the past within it, and it has of the future within it, and it has these generations within it and it has the days of the Messiah within it, and it has the days of Gog and Magog within it: "In the coming out of Israel from Egypt" (Psalms 114:1) is of the past; "Not to us, O Lord" (Psalms 115:1) is of these generations; "I have loved that You heard, O Lord" (Psalms 116:1) is for the days of the Messiah; "All the nations surrounded me" (Psalms 118:10) is for the days of Gog and Magog; "You are my God and I will praise You, my God and I will exalt You" (Psalms 118:28) is for the future to come.