Devarim 20:18

18 That they teach you not to do after all their to’evot (abominations) which they have done unto their elohim; so that ye would sin against Hashem Eloheichem.

Devarim 20:18 Meaning and Commentary

Deuteronomy 20:18

That they teach you not to do after all their abominations,
&c.] This is another reason why they were to be utterly destroyed, not only because of the abominations which they committed, but to prevent the Israelites being taught by them to do the same; wherefore, as before observed from Jarchi, such as became proselytes were suffered to live among them, because there was no danger of idolatry from them, which even proselytes of the gate renounced; and though all other abominations are included, yet this is particularly respected, as appears from the following clause:

which they have done unto their gods;
to the honour of whom not only many superstitious rites and ceremonies were performed, and idolatrous actions committed, but acts of lewdness, and even unnatural uncleanness:

so should ye sin against the Lord your God;
a sin the most provoking to him, as the sin of idolatry was; and cause his anger to rise to such a degree, as to suffer them to be carried captive from the land he gave them to inherit; and which afterwards, was the case, and that through learning the manners and customs of these people; see ( Psalms 106:34-42 ) .

Devarim 20:18 In-Context

16 But of the towns of these people, which Hashem Eloheicha doth give thee for a nachalah, thou shalt save alive nothing that breatheth;

17 But thou shalt utterly put them under cherem of destruction; namely, the Chitti, and the Emori, the Kena’ni, and the Perizzi, the Chivi, and the Yevusi; as Hashem Eloheicha hath commanded thee;

18 That they teach you not to do after all their to’evot (abominations) which they have done unto their elohim; so that ye would sin against Hashem Eloheichem.

19 When thou shalt besiege a town yamim rabbim, in making war against it to take it, thou shalt not destroy the trees thereof by forcing an axe against them; although thou mayest eat of them, thou shalt not cut them down. Are the etz hasadeh men that they should come under your siege?

20 Only the trees which thou knowest that they be not trees for food, thou shalt destroy and cut them down; and thou shalt build siege works against the town that maketh milchamah with thee, until it be subdued.