רב אדא בריה דרב יצחק

Rab Ada, son of Rabbi Yitzchak [Yoma (17a), Zevachim (38a, 111a) and Niddah (54a) Bar Yitzchak]. And some say it was Rabbi Shmuel, son of Rabbi Yitzchak, perhaps they are brothers. [And some say it was Rabbi Shmuel, son of Rabbi Abba, Beitzah (19b) and that matter is discussed in Pesachim (13b) Rabbi Ada, son of Rabbi Ahavah]: