איבו אבוה דרב

Ivo, the father of Rav (as mentioned regarding Abba bar Acha bar Sela), said: Ivo was standing before Rabbi Elazar, son of Rabbi Tzadok, and they brought a willow branch and struck it, but he did not recite a blessing. [Rashi explains: Ivo, the father of Rav, is mentioned in Sukkah (Mishnah 4:2). And in the Yichusim, it is written before Rabbi Elazar, son of Rabbi Yitzchak; perhaps it was difficult for him that Rabbi Elazar ben Tzadok lived before the destruction, and how could he have been in the days of Ivo?

However, in the Asher Yatzar and in Toharot, section 674, the version is Rabbi Elazar, son of Rabbi Tzadok, as explained at length.]