Les Psaumes 118:24 Midrash : Shir HaShirim Rabbah & Midrash Tehillim

Another matter, “let us exult and rejoice in you.” Rabbi Avin began: “This is the day that the Lord has made, we exult and rejoice in Him [bo]” (Psalms 118:24). Rabbi Avin said: We do not know regarding what to rejoice, whether the day, or the Holy One blessed be He.¹⁸¹The word bo in the phrase “we exult and rejoice bo” can alternatively be translated “in it,” meaning the day, or “in Him,” referring to God. Solomon came and specified: “Let us exult and rejoice in You,” in the Holy One blessed be He. In You, in Your salvation; in You, in Your Torah; in You, in fear of You.¹⁸²This is in line with the verse: “Serve the Lord with fear and rejoice with trembling” (Psalms 2:11) (Rabbi David Luria). Rabbi Yitzḥak said: “In You [bakh],” with the twenty-two letters that You wrote for us in the Torah, beit, two, kaf, twenty, that is bakh.

"To the conductor, for the servant of the Lord. This is what the scripture says (Psalms 16:1), 'A psalm of David. Preserve me, O God, for in You I have taken refuge.' Rabbi Yudan in the name of Rabbi Yehuda said, 'Everything that David said in his book, he said corresponding to himself, to all of Israel, and to all times.' Our Master, the Lord of the Universe, You performed miracles for us at night and we sang praises at night, as it says (Exodus 15:2), 'The Lord is my strength and my song, and He has become my salvation; this is my God, and I will praise Him.' And it says (Isaiah 30:29), 'You shall have a song, as in the night when a holy festival is kept; and gladness of heart, as when one sets out to the sound of the flute, to go to the mountain of the Lord, to the Rock of Israel.' You performed miracles for us during the day and we sang praises to You during the day, as it says (Psalms 118:24), 'This is the day that the Lord has made; let us rejoice and be glad in it.'...