After Issachar, Leah bears Zebulun, the sixth son of her own womb. The Targum Pseudo-Jonathan on Genesis 30:20 gives his name a meaning that becomes a pillar of Jewish economic ethics.
Leah says, The Lord hath endowed me with a good dowry by children. This time will the habitation of my husband be with me, because I have borne him six sons: and thus shall his children receive a good portion.
The name Zebulun comes from zevul, "habitation" or "dwelling," and zeved, "gift." Leah hopes Jacob will now truly dwell with her, since she has given him half the tribes.
Then the Targum adds the tribal prophecy: thus shall his children receive a good portion. What portion? The portion that Jacob's deathbed blessing will later specify — Zebulun shall dwell at the haven of the sea, and he shall be for a haven of ships (Genesis 49:13). The tribe of Zebulun will sit on the Mediterranean coast. They will trade. They will grow wealthy by shipping.
The classical partnership: Zebulun the merchant supports Issachar the scholar. Zebulun's boats fund Issachar's yeshiva. The reward for Torah study flows through Zebulun's ledger. Both tribes share the blessing, because the tribe that earns the money and the tribe that studies the law are equal partners in the project of Israel.
This is why Jewish tradition so stubbornly insists on the dignity of tzedakah — not as charity alone, but as partnership. The donor is not a passive sponsor. The donor receives a portion of the scholar's learning, exactly as Zebulun shared Issachar's Torah.
Leah saw this. She named her sixth son for a habitation — the coastal dwelling of a tribe whose ships would make possible the survival of the tribe of study.
The takeaway: commerce and Torah are partners in the Jewish economy. Zebulun at sea, Issachar in the study — one blessing split between them.