Reference for Moed Katan 32:2
יצא רבי חייא ושנה לשני בני אחיו בשוק לרב ולרבה בר בר חנה שמע ר' איקפד אתא ר' חייא לאיתחזויי ליה א"ל עייא מי קורא לך בחוץ ידע דנקט מילתא בדעתיה נהג נזיפותא בנפשיה תלתין יומין
[When] R'Hiyya [next] presented himself before him, Rabbi said to him, 'Iyya!<span class="x" onmousemove="('comment',' Imitating Hiyya's defective pronunciation; he could not correctly pronounce the guttural letters. Cf. Meg. 24b.');"><sup>2</sup></span> Who is calling you outside? ' He realized that he [Rabbi] had taken the matter to heart, and sub mitted himself to [the disability of] a 'reproof' for thirty days. On the thirtieth day Rabbi sent him a message saying 'Come!' Later he sent him a message not to come! (What<span class="x" onmousemove="('comment',' The quotation is here again interrupted.');"><sup>3</sup></span>