Reference for Yevamot 202:15

רב אשי איקלע לבי רב כהנא אמר ליה סליק מר לגבן למלויי בי חמשה אמר רב כהנא הוה קאימנא קמיה דרב יהודה ואמר לי תא סק לזירזא דקני לאיצטרופי בי חמשה אמרו לו למה לי חמשה אמר להו כי היכי דליפרסם מילתא

for it is written, Then his brother's wife shall go up to the gate<span class="x" onmousemove="('comment',' I.e., a specified place. ');">⁵⁶</span> unto the elders.<span class="x" onmousemove="('comment',' Deut. XXV, 7. ');">⁵⁷</span> R. Papa and R. Huna son of R. Joshua arranged a halizah'<span class="x" onmousemove="('comment',' Lit., performed an act'. ');">⁵⁸</span> in the presence of five. In accordance with whose view?<span class="x" onmousemove="('comment',' Did they insist on a quorum of five. ');">⁵⁹</span> Was it in accordance with that of R. Judah? He, surely, had changed his opinion!<span class="x" onmousemove="('comment',' Agreeing that only three are required for a halizah quorum. ');">⁶⁰</span>

Jastrow