John Wesley on Numbers 27:22

And Moses did as the Lord commanded him - It had been little to resign his honour to a son of his own. But with his own hands, first to ordain Eleazar high - priest, and now Joshua chief ruler, while his own children had no preferment at all, but were left in the rank of common Levites: this was more to his glory than the highest advancement of his family could have been. This shews him to have had a principle which raised him above all other lawgivers, who always took care to establish their families in some share of the greatness themselves possessed.