Hallel הלל
Six psalms of praise (113-118) sung on festivals—the Levites sang them in the Temple while the Passover offerings were brought.
"Out of the straits I called to the Lord", "the stone the builders rejected became the cornerstone", "this is the day the Lord has made"—the lines of Hallel—six psalms, 113 to 118—are known by heart because they are sung year after year: on Pesach, Shavuot, Sukkot and Chanukah, and on Passover night at the table, split in two around the meal.
The Mishnah remembers Hallel as belonging to the Temple: three shifts brought the Passover offering, and in each the Levites had time to sing it through. On new moons a "half" Hallel is read—a custom the Talmud treats carefully: the full one belongs to true festivals only. And on Purim there is no Hallel: the reading of the scroll is its praise.
On the timeline
Related
Sources
Chazal: Mishnah, Talmud, midrash, Zohar
- Mishnah Pesachim 5:7 — Hallel sung thrice over the offering
- Taanit 28b — the half Hallel of the new moon
Basis: Talmud and midrash.