GERSHOM (gûr’shŏm, from Heb. gārash, to cast out, but in popular etymology explained as from gēr, stranger, Exod.2.22; Exod.18.3)

GERSHOM gûr’ shəm (גֵרְשֹׁ֖ום, prob. a foreign name of unknown meaning; perhaps unusual form from gä’räs’, to drive out, meaning fugitive, Exod 2:22; 18:3 are better taken as deliberate puns than as popular etymologies). 1. Variant of Gershon (e.g 1 Chron 6:16ff.).

2. The leader of the clan of Phinehas (i.e. “sons of Phinehas”) in Ezra’s return from Babylon (Ezra 8:2).

3. Moses’ oldest son and a clan name for some of Moses’ descendants. Of Moses’ son the Bible offers only genealogical data and, prob., the account of his circumcision (Exod 4:24-26).

Turning to Gershom’s descendants Judges (18:30) tells of the family of Jonathan, the son (i.e. descendant) of Gershom, the son of Moses (variant text from KJV “Manasseh”) which served illegally—as priests for Dan until the Captivity.

In David’s bureaucracy the Gershomites appear along with the sons of Eliezer, Moses’ other son (1 Chron 23:15-17). Of these, Shebuel was “the chief” (i.e. leading family?) of the Gershomites and Rehabiah was the chief of the Eliezerites.

Jehdeiah is listed as an officer of the “sons of Shubael” (variant of Shebuel; ?), and Isshiah for the “sons of Rehabiah” (1 Chron 20; 21). Comparison with ch. 23 indicates that these are variant designations for the Gershomites and the Eliezerites respectively. That is, in 1 Chronicles 24 the two clans are designated by their “chief” or leading families rather than by their ancestral names.

Shebuel, an individual contemporary with David, of the Gershomites was David’s chief treasurer. The designation of the Eliezerites as “his brethren, from Eliezer” may indicate that the Gershomites were the dominant of the two clans (1 Chron 26:24, 25).

International Standard Bible Encyclopedia (1915)

(gereshom, from garash, "to cast out"; explained, however, in Ex 2:22 and 18:3 as from gur, "For he said, I have been a sojourner in a foreign land"):

(1) Firstborn son of Moses and Zipporah. The only details of his life contained in the Pentateuch are the account of his circumcision (Ex 4:25), and his remaining under the care of Jethro, while Moses was in Egypt leading the Exodus. His descendants were numbered among the tribes of Levi (1Ch 23:14). One of them apparently was the Jonathan who officiated as priest of the idolatrous sanctuary at Dan, and whose descendants held the office until the captivity. The Massoretic Text inserts a suspended nun, "n," in the name of Moses (mosheh), causing it to be lead Manasseh, for the purpose, according to tradition, of disguising the name out of respect for the revered Lawgiver. Another descendant described as a "son" was Shebuel, a ruler over the treasuries of David.

(2) A son of Levi, so called in 1Ch 6:16,17,20,43,12,71 (Hebrew 1,2,5,28,47,56); 15:7; elsewhere GERSHON (which see).

(3) A descendant of Phinehas, the head of a father’s house, who journeyed with Ezra from Babylon to Jerusalem in the reign of Artaxerxes (Ezr 8:2).