Rabbi Yitzchak was asked whether he had said a quoted statement, and he responded that he hadn't, as a means of recanting it: Megillah 10a
Responding to a question, "From your own baggage [Mitunach]!": Rosh HaShanah 4a
Rabbi Abba said Beiha got his sharpness of mind from being in Israel, but Rav Yitzchak responded that Beiha had been wise from being in Bavel and in Israel: Temurah 29a
Set of statements on death and debilitation: Shabbat 152a
Set of statements on guarding and storing one's money: Bava Metzia 42a
Set of statements on Gd's Judgment and Rosh HaShanah: Rosh HaShanah 16a-b
Set of statements: Megillah 6a-b; Taanit 8b
Series of Rav Nachman's conversations with Rabbi Yitzchak: Taanit 5a-6a
Rabbi Yitzchak's blessing of Rav Nachman, that like the tree that already possesses all blessings, his children should be like him: Taanit 5b-6a