TT #218 · Parashas Reeh · Fourth Aliyah · Passuk 14:21
You shall not eat any carcass; give it to the stranger within your gates, that he may eat it, or sell it to a foreigner; for you are a holy people to Hashem your God. You shall not boil a kid in its mother’s milk.
Torah Temimah points to Torah Temimah.
Sefaria — Torah Temimah on Deuteronomy 14:21
English: “For you are a holy people” — from where is meat-in-milk forbidden in benefit? It is said here “holy” and elsewhere “there shall be no kadesh.”
Gezerah shavah on kodesh (TT) — extends the ban to benefit.
Benefit from meat-in-milk is forbidden by the holiness comparison.