5 Jethro, Moses' father-in-law, came with his sons and his wife to Moses in the wilderness where he was encamped at the mountain of God.

Matthew Henry's Commentary on Exodus 18:5

Commentary on Exodus 18:1-6

(Read Exodus 18:1-6)

Jethro came to rejoice with Moses in the happiness of Israel, and to bring his wife and children to him. Moses must have his family with him, that while he ruled the church of God, he might set a good example in family government, 1 Timothy 3:5.