Biblical Personalities: Issachar – Or Hachaim Hakadosh
“He saw tranquility that it was good, and the land that it was pleasant, yet he bent his shoulder to bear and he became an indentured servant.” (Genesis 49:15) Issachar correctly evaluates the repose in the World to Come as well as the relative pleasantness on earth. When Jacob added, “He bent his shoulder to bear,” this is a reference to the pain that is part of our earthly existence. “He turned himself,” into someone who serves the Lord as a form of paying tribute.
Another meaning of these last words may be that in return for becoming a willing servant of the Lord, the rest of the population is obligated to pay a tax to assure the Torah scholar of his livelihood.
In the case of Issachar that would be Zebulun who was a seafarer putting much of his wealth at the disposal of Issachar.