Rashi
Jewish
1040–1105
“Yesochar's nobles. The noblemen of Yesochar. This refers to members of the Sanhedrin who were engrossed in Torah study, and who knew and understood the times. They constantly accompanied Devorah, teaching the Yisroelites the laws and precepts. Yesochar's nobles. The "י" in שׇׂרַי [lit. "my" nobles] is ancillary, fulfilling no grammatic function. It is similar to the "י" in "the animals in the field," or "he cut open, for himself, a window." Yesochar with Barak. The remainder of Yesochar's constituency were likewise at Barak's disposal whenever he issued orders. Dispatched to the valley at his heels. He dispatched them on all of his missions—to mobilize the people, and for all military needs. However, in Reuven's equivocation. However, in Reuven's ambiguity was great cunning. "Craftiness of heart," cunning. In what way was he cunning? He straddled the battle lines to learn who would emerge the victor so that he could join them.”