'Heels' in the Bible

“Dan shall be a [venomous] serpent in the way,A fanged snake in the path,That bites the horse’s heels,So that his rider falls backward.

“As for Gad—a raiding troop shall raid him,But he shall raid at their heels and assault them [victoriously].

And Barak summoned [the fighting men of the tribes of] Zebulun and Naphtali to Kedesh, and ten thousand men went up under his command; Deborah also went up with him.

“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.

“Terrors frighten him on every sideAnd chase at his heels.