Three - In Genesis, ten "sons" of Benjamin are mentioned; in Numbers, five (marginal references). Neither list, however, contains Jediael who was perhaps a later chieftain. If so, "son" as applied to him means only "descendant."
It is conjectured that Becher has disappeared from the lists in 1 Chr. 8 and in Numbers, because he, or his heir, married an Ephraimite heiress, and that his house thus passed over in a certain sense into the tribe of Ephraim, in which the "Bachrites" are placed in Numbers Numbers 26:35. He retains, however, his place here, because, by right of blood, he really belonged to Benjamin.

The sons of Benjamin; Bela, and Becher and Jediael - In Genesis 46:21, ten sons of Benjamin are reckoned; viz., Bela, Becher, Ashbel, Gera, Naaman, Eri, Rosh, Muppim, Huppim, and Ard. In Numbers 26:38, etc., five sons only of Benjamin are mentioned, Bela, Ashbel, Ahiram, Shupham, and Hupham: and Ard and Naaman are there said to be the sons of Bela; consequently grandsons of Benjamin. In the beginning of the following chapter, five sons of Benjamin are mentioned, viz., Bela, Ashbel, Aharah, Nohah, and Rapha; where also Addar, Gera, Abihud, Abishua, Naaman, Ahoah, a second Gera, Shephuphan, and Huram, are all represented as grandsons, not sons, of Benjamin: hence we see that in many cases grandsons are called sons, and both are often confounded in the genealogical tables. To attempt to reconcile such discrepancies would be a task as endless as it would be useless. The rabbins say that Ezra, who wrote this book, did not know whether some of these were sons or grandsons; and they intimate also that the tables from which he copied were often defective, and here we must leave all such matters.

[The sons] of Benjamin; Bela, and Becher, and (d) Jediael, (e) three.
(d) Also called Ashbel, (Genesis 46:21; Numbers 26:38).
(e) Who were the chief: or else there were seven in all as it appears in (Genesis 46:21).

The sons of Benjamin; Bela, and Becher, and Jediael, three. Benjamin had ten sons, but three only are mentioned first; the latter of these seems to be the same with Ashbel, Genesis 46:21.

OF BENJAMIN. (1-Chronicles 7:6-12)
The sons of Benjamin--Ten are named in Genesis 46:21, but only five later (1-Chronicles 8:1; Numbers 26:38). Perhaps five of them were distinguished as chiefs of illustrious families, but two having fallen in the bloody wars waged against Benjamin (Judges 20:46), there remained only three branches of this tribe, and these only are enumerated.
Jediael--Or Asbel (Genesis 46. 21).

Sons and families of Benjamin. - In 1-Chronicles 7:6 only three sons of Benjamin-Bela, Becher, and Jediael - are mentioned; and in 1-Chronicles 7:7-11 their families are registered. Besides these, there are five sons of Benjamin spoken of in 1-Chronicles 8:1-2, - Bela the first, Ashbel the second, Aharah the third, Nohah the fourth, and Rapha the fifth; while in 1-Chronicles 7:3-5 five other בּנים are enumerated, viz., אדּר, גּרא (twice), נעמן, שׁפוּפן, and חוּרם. If we compare here the statements of the Pentateuch as to the genealogy of Benjamin, we find in Genesis 46:21 the following sons of Benjamin: Bela, Becher, Ashbel, Gera, Naaman, Ehi (אחי) and Rosh, Muppim and Huppim and Ard (ארדּ); and in Numbers 26:38-40 seven families, of which five are descended from his sons Bela, Ashbel, Ahiram, Shephupham, and Hupham (חוּפם); and two from his grandsons, the sons of Bela, Ard and Naaman. From this we learn, not only that of the בּנים mentioned in Genesis 46:21 at least two were grandsons, but also that the names אחי and מפּים (Genesis.) are only other forms of אחירם and שׁפוּפם (Numbers.). It is, however, somewhat strange that among the families (in Numbers.) the names בּכר, גּרא, and ראשׁ are wanting. The explanation which at once suggests itself, that their descendants were not numerous enough to form separate families, and that they on that account were received into the families of the other sons, though it may be accepted in the case of Gera and Rosh, of whom it is nowhere recorded that they had numerous descendants, cannot meet the case of Becher, for in 1-Chronicles 7:8, 1-Chronicles 7:9 of our chapter mention is made of nine sons of his, with a posterity of 20,200 men. The supposition that the name of Becher and his family has been dropped from the genealogical register of the families in Numbers 26, will not appear in the slightest degree probable, when we consider the accuracy of this register in other respects. The only remaining explanation therefore is, that the descendants of Becher were in reality not numerous enough to form a משׁפּחה by themselves, but had afterwards so increased that they numbered nine fathers'-houses, with a total of 20,200 valiant warriors. The numbers in our register point unquestionably to post-Mosaic times; for at the second numbering by Moses, all the families of Benjamin together numbered only 45,600 men (Numbers 26:41), while the three families mentioned in our verses number together 59,434 (22,034 + 20,200 + 17,200). The tribe of Benjamin, which moreover was entirely destroyed, with the exception of 600 men, in the war which it waged against the other tribes in the earlier part of the period of the judges (Judges 20:47), could not have increased to such an extent before the times of David and Solomon. The name of the third son of Benjamin, Jediael, occurs only here, and is considered by the older commentators to be another name of Ashbel (Genesis 46:21 and Numbers 26:38), which cannot indeed be accepted as a certainty, but is very probable.

Three - They were ten, Genesis 46:25, and five of them are named, 1-Chronicles 8:1, but here only three are mentioned, either because these were most eminent; or because the other families are now extinct.