TT #627 · Parashas Ki Seitzei · Seventh Aliyah · Passuk 25:03
Forty times he shall strike him; he shall not add, lest he continue to strike him beyond these with a great blow, and your brother be degraded before your eyes.
Torah Temimah points to Sifrei Devarim / Makkot 22b.
TT lemma: יַכֶּנּוּ.
Sefaria — Sifrei Devarim / Makkot 22b
English: ‘He shall strike him’ – he shall strike him, and not the ground and not the clothing.
Limiting derash on the object of the verb (Sifrei / Bavli).
The lashes must strike the body itself. Clothing is removed (or torn open) so that the blows are not absorbed by fabric, and the person is positioned so that the strap does not hit the ground.