Cross reference
Judges 12:14
14 He had forty sons and thirty sons' sons, who rode on seventy donkey colts: and he judged Israel eight years.
Judges 5:10
10 Tell [of it], you who ride on white donkeys, You who sit on rich carpets, You who walk by the way.
Judges 10:4
4 He had thirty sons who rode on thirty donkey colts, and they had thirty cities, which are called Havvoth Jair to this day, which are in the land of Gilead.