'Clans' in the Bible

“And the heads of Issachar came with Deborah;As Issachar, so was Barak;Into the valley they rushed at his heels;Among the divisions of ReubenThere were great searchings of heart.

“Why [Reuben] did you linger among the sheepfolds,To hear the piping for the flocks?Among the divisions of ReubenThere were great searchings of heart.