Their father; either,
1. Strictly, and then he is the same who elsewhere is called Jethro, Exodus 3:1 Exo 18 $ oft times; and, as some think, Hobab, Judges 4:11. Or,
2. Largely, i.e. their grandfather, for such are oft called fathers, as Genesis 31:43 2 Kings 14:3, 2 Kings 16:2 18:3; so he was the father of Jethro, or Hobab, Numbers 10:29.