Bereshit Rabbah reads Jacob's blessing of Issachar as a portrait of labor, trade, and Torah scholarship.
The verse calls Issachar "a strong-boned donkey, lying between the sheepfolds" (Genesis 49:14). One reading pairs him with Zebulun: Issachar brings goods by donkey, and Zebulun carries them by ship, as Jacob says that Zebulun will dwell by the shore for ships (Genesis 49:13). Each tribe bears a different kind of weight.
Another reading turns on wordplay. Garem, strong-boned, sounds like garam, caused. A donkey caused Issachar's birth because Leah heard Jacob's donkey and went out to meet him (Genesis 30:16-18). Then the midrash lifts the image higher. Just as a donkey bears a burden, Issachar bears Torah. The sheepfolds become rows of students sitting before the sages, and Issachar becomes the tribe that others consult when a law reaches its deepest difficulty.
“Issachar is a strong-boned donkey, lying between the sheepfolds” (Genesis 49:14). “Issachar is a strong-boned donkey” – Issachar brings by donkey and Zebulun by ships,41Issachar brings merchandise by donkey, and Zebulun takes it and transports it by ship to foreign markets. as it is stated: “He will be a shore for ships” (Genesis 49:13). Another matter: “Issachar is a strong-boned [garem] donkey” – a donkey caused [garam] him: How did Leah know that Jacob was coming?42See Genesis 30:16–18. The donkey brayed, she heard its voice, and went out to greet him. Another matter: “Issachar is a strong-boned donkey” – just as a donkey bears the burden, so, Issachar bears the Torah. “Lying between the sheepfolds” – these are the students who sit on the ground before the Sages, as it is stated: “If you lie between the sheepfolds” (Psalms 68:14).43This is understood to represent rows of students sitting on the ground. Alternatively, the reference is to the continuation of the verse, which states: “The wings of the dove are covered with silver, and its pinions with the shimmer of gold,” and the silver and gold are understood to refer to Torah. Some commentaries assert that the text is corrupted and should reference Judges 5:16. “He saw rest, that it was good, and the land, that it was pleasant; and he bowed his shoulder to bear, and he became subject to a tribute of labor” (Genesis 49:15). “He saw rest, that it was good” – this is Torah, as it is written: “For a good lesson I have given you” (Proverbs 4:2). “He became a subject to a tribute of labor ” – what is the tribute? This is a halakha regarding which they erred and they would seek it from them.44When scholars would be unsure about a halakha, they would consult the sages of Issachar. Likewise it says: “Sent into the valley [ba’emek] on foot” (Judges 5:15) – in the depths [beomka] of halakha.