Behold, thou shalt sleep with thy fathers (cf. 2 Samuel 7:12; Psalms 13:3; Psalms 76:5; Daniel 12:2; Matthew 27:52; John 11:11; 1 Thessalonians 4:14). "The death of men, both good and bad, is often called a sleep, because they shall certainly awake out of it by resurrection" (Peele).
Go a whoring (cf. Exodus 34:15; 2:17) after the gods of the strangers of the land; literally, after gods of strangeness of the land; i.e. after gods foreign to the land, as opposed to Jehovah, the alone proper God of the land he had given to them.