On this daf, we find the Mishnah that whoever recounts a Torah concept in the name of its originator brings redemption to the world, as is well known. What are less known are the guidelines that are provided elsewhere: If there is a string of commentators, one needs only to provide the first and last references.
Someone once asked the Brisker Rov if it is an actual halachic prohibition to relate another’s Torah thought without mentioning his name.
“No, this is only a middas chassidus,” he replied.
“But the Medrash Tanchuma in Bamidbar compares this to one who actually steals.”
“Correct,” replied the Rov. “But that is only discussing one who relates the Torah of another as if it’s his own. If one says, ‘I heard such-and-such,’ he has not transgressed the prohibition of stealing. He has merely failed to live up to a middas chassidus.”
Rav Isser Zalman Meltzer, in his seminal work Even Ha’azel, wrote: “The Kesef Mishnah writes in the name of Tosafos…” His son, Rav Tzvi Yehudah Meltzer, asked him about this. “Why bring in the Kesef Mishnah at all? You don’t discuss anything he says, just the Tosafos he brings. Why not just write ‘Tosafos says…’?”
Rav Isser Zalman answered, “I cited the Kessef Mishnah because I felt gratitude for his work. When I was writing this piece, I had forgotten that Tosafos discusses this. Since I was reminded by seeing the Kesef Mishnah, I specifically quoted it in his name” (Eved Hamelech).