TT #737 · 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 101b.
TT lemma: מֵעַל רַגְלוֹ.
מֵעַל רַגְלוֹ – לְמַטָּה מִן הָאַרְכּוּבָה; לְמַעְלָה מִן הָאַרְכּוּבָה לֹא.
English: “From upon his foot” — below the knee; above the knee is invalid.
On the daf / in context: The removal must be from the foot proper, not from higher on the leg.
Derash limiting the location of the removal.
The shoe must be removed from below the knee; removal from above the knee is invalid.