Psalms 141:4

4. Incline not my heart As in Psalms 141:3 he would have the “door” of his “lips” guarded, so now he would have his “heart” rightly inclined. The prayer is against being abandoned to the pressure and tendency of external circumstances. If left to himself he would fall into sin.

Practise wicked works Literally, To practise practices in wickedness. The habit of evil doing, into which he was in danger of insensibly gliding by the contagion of surrounding example, he here deprecates.

Not eat of their dainties Neither at their idol feasts nor as a guest at their social entertainments; thus tacitly condemning their practices.