The lexica agree that the derivation is uncertain. BDB says outright that the etymology and meaning are dubious, while HALOT, Gesenius and DCH file the name under the root שׂכר, "to hire, to reward," alongside שָׂכָר ("wage"), שֶׂכֶר and שָׂכִיר ("hired laborer"). Yair Zakovitch reads Genesis 30:16 and 30:18 as a deliberate double name-derivation rather than a seam between sources, which fits the two standard reconstructions: יֵשׁ שָׂכָר ("there is a reward") and אִישׁ שָׂכָר ("man of hire"), the latter judged the more probable base by BDB and argued by Wellhausen. Martin Noth classified the name among the Israelite sentence-names, and a verbal reading of the initial yod ("he grants a reward") remains live; non-Hebrew proposals include Wenham's Amorite parallel from Mari and the older suggestion of C. J. Ball that the name means "man of the god Sokar." The orthography is best treated as a split in tradition rather than a scribal error: Ben Asher, whose text the printed Hebrew Bible follows, treats the second sibilant as written but unread, while Ben Naphtali, the Samaritan Pentateuch and the Temple Scroll preserve a double reading, and the Greek, Latin and Syriac versions side with the single pronunciation.
Historical reconstruction is far less secure, and every position below should be weighed as a hypothesis rather than a finding. Albrecht Alt's settlement model read the tribe as a group that entered the Canaanite-dominated Jezreel plain and took on corvee obligations to the city-states, and Noth grouped Issachar with the Leah tribes while treating it as a late accretion to that core and the twelve-tribe system as substantially schematic. Nadav Na'aman has argued that most of Issachar's inheritance lay outside any early Israelite polity and was absorbed only under David, and Israel Finkelstein treats the genealogical tribal system as a literary construct rather than a premonarchic kinship reality. On Genesis 49:14-15 the negative reading of Gunkel and von Rad is answered by de Hoop and Heck, with Zobel in between; all sides agree that the term rendered "strong-boned" connotes strength rather than gauntness. The proposed identification of Issachar with an Egyptian place name from the reign of Amenhotep III (Manfred Gorg, Pieter van der Veen) is a minority position whose related readings have been rejected by Adrom, de Hulster and Ritner, and it should not be presented as established. On 1 Chronicles 12:32 the calendrical reading is Targumic and rabbinic (Genesis Rabbah, b. Yoma 26a, the Targum on Chronicles), while the commentators read ordinary political sagacity.