AV HA-RAḤAMIM (Heb. אַב הָרַחֲמִים; "Merciful Father"), memorial prayer for Jewish martyrs and martyred communities. This prayer, by an unknown author, was composed in memory of the martyrs massacred in Germany during the First Crusade. It is first known from a prayer book dated 1290. The prayer emphasizes the merit of the martyrs who died for kiddush ha-Shem. Several scriptural verses (Deut. 32:43; Joel 4:21; Ps. 79:10; 9:13; 110:6, 7) are quoted, and God is asked to remember the martyrs, to avenge them, and to save their offspring. The wording of the last part of the prayer, invoking Divine retribution on the persecutors, has undergone many changes. Originally this prayer was recited in southern Germany only on the Sabbaths preceding Shavuot and the Ninth of Av and at the conclusion of the Hazkarat Neshamot (Yizkor) memorial service. In the Ashkenazi ritual it became part of the Sabbath morning service. In the Polish rite it is recited either every Sabbath (except when the Prayer for the *New Moon is said, Sabbath falls on a New Moon, or a circumcision takes place), or only on all the Sabbaths of the Omer period between Passover and Shavuot, and on those of the Three Weeks between the Fast of Tammuz and the Ninth of Av. The prayer is recited after the Torah reading before the scroll is returned to the Ark (see Magen Avraham, Sh. Ar., oh 284:7). Another short prayer of the same name "May the Father of mercy have mercy upon a people that has been borne by Him," etc., is recited in Orthodox synagogues immediately before the reading from the Torah.
Hertz, Prayer, 482–3, 510–5; Elbogen, Gottesdienst, 203; Davidson, Oẓar, 1 (1924), 3, no. 40.