A Commentary, Critical, Practical, and Explanatory on the Old and New Testaments, by Robert Jamieson, A.R. Fausset and David Brown  at sacred-texts.com
1 Chronicles 7:1
ch1 7:1SONS OF ISSACHAR. (Ch1 7:1-5)
Jashub--or Job (Gen 46:13).
1 Chronicles 7:2
ch1 7:2whose number was in the days of David two and twenty thousand and six hundred--Although a census was taken in the reign of David by order of that monarch, it is not certain that the sacred historian had it in mind, since we find here the tribe of Benjamin enumerated [Ch1 7:6-12], which was not taken in David's time; and there are other points of dissimilarity.
1 Chronicles 7:3
ch1 7:3five: all of them chief men--Four only are mentioned; so that as they are stated to be five, in this number the father, Izrahiah, must be considered as included; otherwise one of the names must have dropped out of the text. They were each at the head of a numerous and influential division of their tribe.
1 Chronicles 7:5
ch1 7:5fourscore and seven thousand--exclusive of the 58,600 men which the Tola branch had produced (Ch1 7:24), so that in the days of David the tribe would have contained a population of 45,600. This large increase was owing to the practice of polygamy, as well as the fruitfulness of the women. A plurality of wives, though tolerated among the Hebrews, was confined chiefly to the great and wealthy; but it seems to have been generally esteemed a privilege by the tribe of Issachar, "for they had many wives and sons" [Ch1 7:4].
1 Chronicles 7:6
ch1 7:6OF BENJAMIN. (Ch1 7:6-12)
The sons of Benjamin--Ten are named in Gen 46:21, but only five later (Ch1 8:1; Num 26:38). Perhaps five of them were distinguished as chiefs of illustrious families, but two having fallen in the bloody wars waged against Benjamin (Jdg 20:46), there remained only three branches of this tribe, and these only are enumerated.
Jediael--Or Asbel (Genesis 46. 21).
1 Chronicles 7:7
ch1 7:7the sons of Bela--Each of them was chief or leader of the family to which he belonged. In an earlier period seven great families of Benjamin are mentioned (Num 26:38), five of them being headed by these five sons of Benjamin, and two descended from Bela. Here five families of Bela are specified, whence we are led to conclude that time or the ravages of war had greatly changed the condition of Benjamin, or that the five families of Bela were subordinate to the other great divisions that sprang directly from the five sons of the patriarch.
1 Chronicles 7:12
ch1 7:12Shuppim also, and Huppim--They are called Muppim and Huppim (Gen 46:21) and Hupham and Shupham (Num 26:39). They were the children of Ir, or Iri (Ch1 7:7).
and Hushim, the sons--"son."
of Aher--"Aher" signifies "another," and some eminent critics, taking "Aher" as a common noun, render the passage thus, "and Hushim, another son." Shuppim, Muppim, and Hushim are plural words, and therefore denote not individuals, but the heads of their respective families; and as they were not comprised in the above enumeration (Ch1 7:7, Ch1 7:9) they are inserted here in the form of an appendix. Some render the passage, "Hushim, the son of another," that is, tribe or family. The name occurs among the sons of Dan (Gen 46:23), and it is a presumption in favor of this being the true rendering, that after having recorded the genealogy of Naphtali (Ch1 7:13) the sacred historian adds, "the sons of Bilhah, the handmaid, who was the mother of Dan and Naphtali." We naturally expect, therefore, that these two will be noticed together, but Dan is not mentioned at all, if not in this passage.
1 Chronicles 7:13
ch1 7:13OF NAPHTALI. (Ch1 7:13)
Shallum--or Shillem (Gen 46:24).
sons of Bilhah--As Dan and Naphtali were her sons, Hushim, as well as these enumerated in Ch1 7:13, were her grandsons.
1 Chronicles 7:14
ch1 7:14OF MANASSEH. (1Ch. 7:14-40)
The sons of Manasseh--or descendants; for Ashriel was a grandson, and Zelophehad was a generation farther removed in descent (Num 26:33). The text, as it stands, is so confused and complicated that it is exceedingly difficult to trace the genealogical thread, and a great variety of conjectures have been made with a view to clear away the obscurity. The passage [Ch1 7:14-15] should probably be rendered thus: "The sons of Manasseh were Ashriel, whom his Syrian concubine bare to him, and Machir, the father of Gilead (whom his wife bare to him). Machir took for a wife Maachah, sister to Huppim and Shuppim."
1 Chronicles 7:21
ch1 7:21whom the men of Gath . . . slew, &c.--This interesting little episode gives us a glimpse of the state of Hebrew society in Egypt; for the occurrence narrated seems to have taken place before the Israelites left that country. The patriarch Ephraim was then alive, though he must have arrived at a very advanced age; and the Hebrew people, at all events those of them who were his descendants, still retained their pastoral character. It was in perfect consistency with the ideas and habits of Oriental shepherds that they should have made a raid on the neighboring tribe of the Philistines for the purpose of plundering their flocks. For nothing is more common among them than hostile incursions on the inhabitants of towns, or on other nomad tribes with whom they have no league of amity. But a different view of the incident is brought out, if, instead of "because," we render the Hebrew particle "when" they came down to take their cattle, for the tenor of the context leads rather to the conclusion that "the men of Gath" were the aggressors, who, making a sudden foray on the Ephraimite flocks, killed the shepherds including several of the sons of Ephraim. The calamity spread a deep gloom around the tent of their aged father, and was the occasion of his receiving visits of condolence from his distant relatives, according to the custom of the East, which is remarkably exemplified in the history of Job (Job 2:11; compare Joh 11:19).