Parashas Vayikra · Aliyah 1 · Passuk 1
Chabad.org — English translation + Rashi
Torah Temima points to Yoma 4b (same amud, immediately after the previous derasha; verified).
E-Daf.com — Tsurras Hadaf (size=3)
HebrewBooks / Shas PDF of the daf
English: “Saying” (leimor) — Rabbi Musya son of the son of Rabbi Masya said in the name of Rabbi Musya the Great: From where do we know that one who says something to his fellow is under a prohibition not to say it further until [the original speaker] says to him, “Go, say [it]”? As it is stated: “And Hashem spoke to him from the Tent of Meeting, saying.”
Custom (restrictive reading of leimor, classically associated with “do not say”) — private speech may not be repeated without explicit authorization. Related in spirit to notariqon-style readings (cf. R’ Eliezer’s list) but not formally numbered here.
Private speech is not to be repeated unless the original speaker explicitly authorizes it. (The restriction does not apply when the matter was said for the listener’s own benefit.)