AVINU SHE-BA-SHAMAYIM (Heb. אָבִינוּ שָׁבַּשָׁמַיִם; "Our Father in Heaven"), form of adoration frequently found at the beginning of prayers of petition, based on the rabbinic epithet of God as "Father in Heaven." The description of God as "Father" occurs in the Bible, e.g., "Thou art our Father…" (Isa. 63:16), or "O Lord, Thou art our Father; we are the clay, and Thou our potter" (ibid. 66:8), and the prayer of David in i Chronicles 29:10, "Blessed be Thou, O Lord, the God of Israel, our Father for ever and ever." The tendency to describe God's relationship to Israel as analogous to the intimate father-child relationship was balanced by the desire to emphasize God's sovereignty and transcendence. Consequently, the rabbis of the talmudic period in formulating prayers preferred formulae in which God's position as King and Ruler is stressed as much as the father-child relationship. Piety and observance of the Law are described in early rabbinic parlance as "doing the will of our Father in heaven." The intimate relationship with God, as cultivated in particular by Eastern European Ḥasidism, found expression in the Yiddish language too, where, especially in private petitions and prayers, reference to God as "Father in Heaven" ("foter in himl," "tate in himl") was common.
J. Heinemann, Ha-Tefillah bi-Tekufat ha-Tanna'im ve-ha-Amora'im (19662), 116, 120.