Responsa for Menachot 83:9

רבינא ורב סמא הוו יתבי קמיה דרב אשי חזייה רב סמא לקרניה דגלימיה דרבינא דסתר ובצר ממלא קשר גודל אמר ליה לא סבר לה מר להא דר' יעקב אמר ליה בשעת עשייה איתמר

Rabina and R'Sama were once sitting before R'Ashi when R'Sama noticed that the [edges around the hole in the] corner of Rabina's garment had frayed and [the fringe] was now less than the distance of the first joint of the thumb away [from the corner], and he said to him, 'Does not my Master accept R'Jacob's teaching? ' He replied, 'That rule was intended to apply only at the time when it was first made'. [R'Sama] became embarrassed, whereupon R'Ashi said to him, 'Do not be upset, for one of them<span class="x" onmousemove="('comment',' Sc. scholars from Palestine, of whom Rabina was one.');">¹⁰</span>

Teshuvot Maharam