5:1 he defiled the couch of his father Because Reuben slept with his father’s concubine, he was not given the preeminence typically due the firstborn son. See Gen 35:22 and note; compare Gen 49:4 and note.

Joseph The comments in 1 Chron 5:1–2 explain that while Reuben was technically “firstborn of Israel,” his actions disqualified him from the benefits of his firstborn status. The birthright was given to Joseph, the favorite son of Jacob (Gen 48:15–22).

5:2 Judah Jacob’s three eldest sons all made themselves unworthy to receive the birthright and blessing of the firstborn (Gen 34–35). The Chronicler acknowledges that Judah was next in line, but the birthright still went to Joseph (second youngest of twelve sons). Nevertheless, Judah was blessed in significant ways and attained greater status, power, and prestige than most of the other tribes.

5:3 The sons of Reuben the firstborn of Israel The four men identified here are consistently listed as the sons of Reuben and the founders of the Reubenite clans (Gen 46:9; Exod 6:14; Num 26:5–6).

5:4 The sons of Joel This genealogy of Joel is not directly connected with the previous verse, so it is unknown how many generations came between Reuben and Joel. The seven generations listed in 1 Chron 5:4–6 that lead up to the Syro-Ephraimite War (ca. 734–732 bc) are not enough to cover the centuries from Reuben to the time of Tiglath-Pileser. The names listed here are unattested outside this passage.

5:6 deported into exile According to 2 Kgs 15:29, Tiglath-Pileser III conquered territory in Israel when he invaded the region during the Syro-Ephraimite War. He deported people from those regions and took them into exile in Assyria (compare 1 Chr 5:26). It is likely that those deported would be prominent people like Beerah, chief of the Reubenites. Deporting leaders was an effective way to control a rebellious region by removing the leadership (compare 2 Kgs 24:14).

5:7 his kinsmen Refers to other relatives of Beerah. Bela, mentioned in 1 Chr 5:8–9, also is a descendant of Joel through his son Shema (or Shemaiah; v. 4).

5:10 war against the Hagrites The Hagrites appear to have been a seminomadic group in the Transjordan region. Outside of 1 Chronicles, they are mentioned only in Psa 83:6. According to 1 Chr 5:18–22, the tribes of Gad and Manasseh also were involved in this conflict.

5:11 the sons of Gad The tribe of Gad lived north of the tribe of Reuben.

Salecah This town marks the eastern edge of the Transjordan and the approximate border between Bashan and Gilead (Deut 3:10; Josh 12:5).

5:18 The Reubenites, the Gadites, and the half-tribe of Manasseh The tribes of the Transjordan are often mentioned together (e.g., Deut 3:12–16; 29:7–8; Josh 13:8–31; 1 Chr 12:37). They are unified by their inheritance of territory east of the Jordan River, separate from the other tribes.

5:19 Jetur, Naphish Descendants of Ishmael according to 1:30–31 (compare Gen 25:15).

5:20 for they cried out to God As with the prayer of Jabez (1 Chron 4:10 and note), the Chronicler emphasizes that God answers prayers. See Num 32:33 and note.

5:23 Manasseh The half-tribe of Manasseh lived in the Bashan region of the Transjordan, north of the territory of Gad.

5:24 mighty men of strength The Hebrew phrase used here, gibbor chayil, denotes men of strength or men of ability. It often refers to warriors (1 Chron 28:1; see 26:6 and note).

5:25 they transgressed against the God of their ancestors The Chronicler attributes this first phase of the Assyrian exile to the tribes’ breach of faith, using the Hebrew word ma'al.