Jastrow: תּוֹרְתָּא

תּוֹרְתָּא, תּוֹרְתָא, תּוֹרְתָּה, בֶּן תּ׳ pr. n. m. (Johanan) ben Torta, a Tannai. Y. Taan. IV, 68ᵈ bot.; Lam. R. to II, 2. Num. R. s. 79; Tosef. Men. XIII, 22. Pesik. R. s. 14 (describing the origin of the name) אמר ומה אם פרה … מיד בא ונתגייר … יוחנן בן ת׳ he said, if a cow that has no speech and no mind recognized her Creator, should I whom my Maker has created in his image … not go and acknowledge my Creator? He went and became a Jew, and studied and grew efficient in the Law, and they named him Johanan ben T. (son of a cow); and to this day our teachers quote Hălakhah in his name.