Babylonian amora, who flourished in the fourth century; disciple of Ḥisda (Shab. 54b, 66a). He emigrated to Palestine, where R. Jonah gave him tithes, saying, "Not because Aḥa is of priestly descent, but because he is assiduous in the study of the Torah," quoting 2 Chronicles 31:4 in support of this action. Aḥa himself represents King David as faithfully discharging the duty of tithe-giving, quoting Ps. 9, implying that David took care that nothing which was not duly tithed should enter his body. The enforcement of this resolution was, according to Aḥa, David's object in appointing Jonathan, son of Uzziah, "over the store-houses in the fields, in the cities, and in the villages, and in the castles" (1 Chronicles 27:25; PesiḲ. § 9, 98b; Tan., Reeh 14).
For another Aḥa b. 'Ulla, see Bacher, "Ag. Pal. Amor." 3:654 et seq.