TT #731 · Parashas Ki Seitzei · Seventh Aliyah · Passuk 25:09
Then his yevamah shall approach him in the presence of the elders, and draw his shoe off his foot, and spit in his face, and respond and say: “Thus shall be done to the man who will not build up his brother’s house.”
Torah Temimah points to Yevamot 101a (Rava).
TT lemma: לְעֵינֵי הַזְּקֵנִים.
אָמַר רָבָא: צְרִיכִי דַּיָּינֵי לְמֶחֱזֵי רוֹקָא כִּי נָפֵיק מִפּוּמָא דְּיַבָּמָה, דִּכְתִיב לְעֵינֵי הַזְּקֵנִים וְיָרְקָה.
English: Rava said: The judges must see the spittle as it leaves the mouth of the yevamah, for it is written “before the eyes of the elders and she shall spit.”
On the daf / in context: The act of spitting must be observed at the moment it occurs.
Derash requiring visual observation of the spitting.
The judges must see the spittle leave the yevamah’s mouth.