Yevamot 101B

שנאמר: ״כלך יפה רעיתי ומום אין בך״. ואידך: ההוא ״לעיני״ מאי עביד ליה? ההוא לכדרבא הוא דאתא. דאמר רבא: צריכי דייני למיחזי רוקא דקא נפיק מפומא דיבמה, דכתיב: ״לעיני הזקנים ... וירקה״.

This is as it is stated: “You are entirely beautiful, my love, and there is no blemish in you” (Song of Songs 4:7). If the Elders conducting ḥalitza needed to be expert judges, there would be no reason to explicitly exclude the blind, as they are unfit to be judges in a regular court. Evidently it is permitted for laymen to be judges for ḥalitza, and only blind individuals are excluded. The Talmud asks: And the other Sage, the first tanna, what does he do with the verse “before the eyes of”? The Talmud answers: That verse comes for that which Rava taught, as Rava said: The judges must see the spittle that exits from the mouth of the yevama as part of the ceremony of ḥalitza, as it is written: “His yevama should approach him, before the eyes of the Elders, and remove his shoe from on his foot and spit before him and respond and say: So should it be done to the man who does not build his brother’s house” (Deuteronomy 25:9).

ואידך נמי, מיבעי ליה לכדרבא! אין הכי נמי, ואלא הדיוטות מנא ליה? נפקא מ״בישראל״⁠ — ישראל כל דהו.

The Talmud asks: If so, the other Sage, R' Yehuda, should also require “before the eyes” to teach Rava’s statement. The Talmud answers: Yes, this is so, as R' Yehuda understands “before the eyes” as requiring the judges to see the spittle. But then from where does he derive the eligibility of laymen? He derives it from the phrase: “In Israel,” in the verse “And his name should be called in Israel” (Deuteronomy 25:10), which indicates that any Israelite, even one who is not an expert judge, may preside over ḥalitza.