Ames: The source for replying “same to you” is the Gemara in Megillah (27b). Rav blessed his student Rav Huna, and the blessing came true. Rav then told Rav Huna that he should have responded to the bracha with “and the same to Mar (i.e. Rav).” According to Rashi, Rav told Rav Huna “You should have blessed me that I should also receive the same bracha, for perhaps it was an eis ratzon and the blessing would have been fulfilled for me as well.” The Aruch L’ner (Rav Ya’akov Ettlinger), in his hakdama to maseches Yevamos, quotes the following interpretation of Rashi that he heard from his father, Rav Aharon Ettlinger:
Chazal state that people don’t tend to be jealous of their children or their students, and Rav CERTAINLY wasn’t jealous of his student Rav Huna. Rather, out of his humility, Rav wished to convey the impression that the bracha only came true because it was given at a favorable time. This way, he intended to preclude attribution of the bracha’s fulfillment to his own zechus.