The Psalms of Ascent (שִׁירים הַמַּעֲלוֹת Shirim haMa’alot, Psalms 120-135) are called such because they relate to the ancient practice of publicly singing these songs when going to God’s house in Yerushalayim (Jerusalem). These poems are connected to סוכת Sukkot, the Feast of Tabernacles, which runs for seven days from the 15th day of the seventh month on the biblical calendar.
