TAḤANUN (Heb. תַּחֲנוּן; "supplication"), name of a prayer which is a *confession of sins and a petition for grace. It forms part of the daily morning and afternoon services and is recited after the ḥazzan's repetition of the *Amidah. The Taḥanun begins with a silent recital of David's utterance after being rebuked by the prophet Gad for his sin of numbering the people (ii Sam. 24:14), "let us fall, I pray thee, into the hand of the Lord, for His mercies are many, but let me not fall into the hand of men." It is, therefore, also called nefilat appayim ("prostration prayer," lit. "falling on the face"). Since prostration during petitions is mentioned in the Bible (Deut. 9:18; Josh. 7:6), it was customary to recite the Taḥanun prostrated. In modern times, however, the prayer is recited in a seated position with lowered head and face buried in the bend of the arm. This position is assumed only where there is a Torah Scroll to designate the sanctity of the place. In the Sephardi ritual, it is customary to start the Taḥanun with a silent confession of sins (Viddui), followed by ii Samuel 24:14 (as in the Ashkenazi ritual). The central part of Taḥanun is a penitential psalm, Psalm 25 in the Sephardi, and Psalm 6 in the Ashkenazi ritual. The Taḥanun is supplemented by additional penitential prayers and piyyutim. In the Ashkenazi rite there follows part of a piyyut (Shomer Yisrael) which also occurs in the *seliḥot liturgy. The last passage of the Taḥanun, starting with a quotation from ii Chronicles 20:12 (Va-anaḥnu lo neda mah na'aseh), is a shortened form of the whole prayer and was instituted so that latecomers to the morning service could attend the reading from the Torah. The Taḥanun prayer is omitted on Sabbaths, festivals, semiholidays, New Moons, from the Minḥah service preceding these special days, during the month of Nisan, and on the Ninth of Av. At a circumcision in the synagogue, when a bridegroom attends the service during the first seven days after his wedding, and at prayers held at the homes of mourners, the Taḥanun is also omitted.
The origin of the Taḥanun dates back to the talmudic period in Babylonia. Although the prayer was known as nefilat appayim, many rabbis, such as Eleazar b. Hyrcanus (bm 59b), *Abbaye, *Rava, and especially *Rav refused to prostrate at this prayer, either because they considered complete prostration forbidden outside the Temple in Jerusalem or because they regarded it as not obligatory for a distinguished personage (Meg. 22b; Ta'an. 14b). By the time of the geonim the posture had already been modified to sitting (or half-sitting), with the head inclined on the arm. The exact date of the various parts making up the Taḥanun cannot be established with certainty. The view that the Taḥanun was originally a supplication supplemented by confession of sins recited in private without fixed form is strengthened by the fact that there is considerable variety in the versions given in the various prayer books (e.g.,*Saadiah Gaon, *Maimonides, etc.). Its final version evolved only in the 16th century.
Eisenstein, Dinim, 270, 435–6; Baer, S., Seder, 112–9; Elbogen, Gottesdienst, 73–81; Hertz, Prayer, 168–87; E. Levy, Yesodot ha-Tefillah (19522), 177–9; E. Munk, The World of Prayer, 1 (1961), 161–70; Abrahams, Companion, lxxviff.