Devarim — Lo Talin
Deuteronomy 21:23
The Torah commands 'you shall surely bury him' (kavor tikbrennu), deriving the positive commandment of burial from the verse about the executed criminal. This is the foundational biblical source for kevurah and the prohibition of cremation.
לֹא־תָלִ֨ין נִבְלָת֜וֹ עַל־הָעֵ֗ץ כִּֽי־קָב֤וֹר תִּקְבְּרֶ֙נּוּ֙ בַּיּ֣וֹם הַה֔וּא כִּֽי־קִלְלַ֥ת אֱלֹהִ֖ים תָּל֑וּי וְלֹ֤א תְטַמֵּא֙ אֶת־אַדְמָ֣תְךָ֔ אֲשֶׁר֙ יְהֹוָ֣ה אֱלֹהֶ֔יךָ נֹתֵ֥ן לְךָ֖ נַחֲלָֽה׃ {ס}
you must not let the corpse remain on the stake overnight, but must bury it the same day. For an impaled body is an affront to God: you shall not defile the land that the ETERNAL your God is giving you to possess.