JAKIN (jā'kĭn, Heb. yâkhîn, he will set up)

The fourth son of Simeon (Gen.46.10; Jarib in 1Chr.4.24). Founder of the clan of Jakinites (Num.26.12).One of the priests in Jerusalem during the Captivity (Neh.11.10).During David’s reign a leader of the twenty-first course of priests (1Chr.24.17).

JACHIN jā’ kĭn (יָכִ֣ין, He shall establish). 1. The fourth son of Simeon and head of the Jachinite tribe (Gen 46:10; Exod 6:15; Num 26:12; Jarib in 1 Chron 4:24).

2. One of the priests who lived in Jerusalem after the Exile (1 Chron 9:10; Neh 11:10). It is possible, however, that the name may here be used as a family name denoting the priests in the twenty-first course, or the course of which Jachin was the head. In a list of six priests (1 Chron 9:10-13), three of them have names that may be found in the list of courses (24:17) and two of the remaining names (Adaiah and Maasai) are carefully traced back to ancestors who were the heads of courses.

3. The head of the twenty-first course of priests (1 Chron 24:17).

International Standard Bible Encyclopedia (1915)

(yakhin, "he will establish"):

(1) The 4th son of Simeon (Ge 46:10; Ex 6:15; Nu 26:12). In 1Ch 4:24 his name is given as "Jarib" (compare the King James Version margin, the Revised Version margin). "Jachinites," the patronymic of the family, occurs in Nu 26:12.

(2) Head of the 21st course of priests in the time of David (1Ch 24:17). It is used as a family name in 1Ch 9:10, and as such also in Ne 11:10, where some of the course are included in the list of those who, having returned from Babylon, willingly accepted the decision of the lot, and abandoned their rural retreats to become citizens and guardians of Jerusalem (Ne 11:1 f).