Verse 1: There was also a lot for the tribe of Manasseh; for he was the (Gen. 41:51; 46:20; 48:18) firstborn of Joseph; to wit, for (Gen. 50:23; Num. 26:29; 32:39, 40; 1 Chron. 7:14) Machir the firstborn of Manasseh, the father of Gilead: because he was a man of war, therefore he had (Deut. 3:15) Gilead and Bashan.
[A lot fell to the tribe of Manasseh (for he is the first-born of Joseph)] A lot, that is, an inheritance assigned by the casting of lots (Vatablus). Question: To what end are these last words added? Responses: 1. Either, 1. as the reason why two parts were allotted to Manasseh, because he was the first-born. See Deuteronomy 21:17. For, that in Genesis 48:18 Ephraim was set before Manasseh, is not to be understood as a transfer of the primogeniture, but as a prophetic blessing of the offspring (Junius). Jacob did indeed prophesy greater things for Ephraim eventually, Genesis 48:19, but he did not take the right of the first-born from Manasseh: neither did Manasseh deserve that (Grotius). If you wish the כִּי/for to be a note of cause, rightly, if I am not mistaken, you would be saying that the condition of his birth is recalled as the cause of the wealth of Manasseh, and of the possessions received on both sides of Jordan (Masius). To others this reason is not satisfying: For it is not likely that in Genesis 48 Jacob wanted to ascribe three portions to Joseph, but only two, in such a way that Joseph enjoys the right of primogeniture, not Manasseh; and that the sons of Joseph come into possession of Canaan with the rest of the sons with an equal share only: And Manasseh was indeed the first-born with respect to Ephraim, but not in comparison with the other sons of Jacob, among whom the division was made. Moreover, there appears to have been no other reason for the division of this Tribe into two parts, than that the region on the other side of Jordan was not sufficient for all those, and so a possession was to be sought for the other part on this side of Jordan (Bonfrerius). Or, 2. this clause was added, so that the reader might observe that by that outcome of the lot was illustriously ratified the judgment of Jacob in Genesis 48:14, which I was just saying. The כִּי is to be translated in this way, now, Now, he was the first-born, etc. (Masius). Or, 3. he gives the reason why Manasseh, who was not of the sons of Jacob, nevertheless came into a portion of Canaan with the other sons; namely, because he was a son of Joseph (Bonfrerius out of Lapide), and also the firstborn. The same was able to be said concerning the lot of Ephraim; but the Scripture, passing over it there in silence, expressed it here, leaving the one to be gathered from the other (Bonfrerius).
He was the first-born of Joseph: the sense is, though Ephraim was to be more potent and numerous, yet Manasseh was the first-born, and had the privilege of the first-born, which was translated to Joseph, to wit, a double portion; and therefore though this were but half the tribe of Manasseh, yet they are not made inmates to Ephraim, but have a distinct lot of their own, as their brethren or other half tribe had beyond Jordan.
[To Machir, the first-born of Manasseh] Nay, he was an only child (Lapide, Menochius). But Scripture is wont to call even those that have no brothers the first-born. Thus Christ, in Matthew 1, is the first-born (Menochius).
Machir; the only son of Manasseh, who therefore is here, and Judges 5:14, put for the whole tribe. The first-born; so even only sons are sometimes called, as Matthew 1:25: see on Exodus 4:22.
[The father of Gilead] [They vary:] The founder of Gilead (Junius and Tremellius). Some explain father as the Acquirer; for he begat, as it were, or gave birth to, that is, he acquired, that land. Now, Gilead here is a region, by ellipsis of the word אָרֶץ/land, which is expressed in Numbers 32:1. Although it appears simpler and closer to the truth to take each name properly here, from verse 3 (Piscator). Therefore, others translate it, and the father of Gilead (Munster, Tigurinus, similarly the Septuagint, Syriac, Pagnine, Castalio). All the families of the Manassites, on both sides of Jordan, are descended from Gilead, as it is evident from this place, and from Numbers 26:29, etc. But the name of Gilead stuck to the lands on the other side of Jordan (Bonfrerius on verses 1 and 2).
The father of Gilead; or, and the father, or who was also the father of Gilead; not of the land of Gilead, but of the man Gilead, who was Machir’s son, Numbers 26:29.
[Who was a fighter] Hebrew: man of war. But where did he put forth that martial spirit and skill? For, since Gilead was born with his grandfather Joseph yet living, Genesis 50:22, it certainly appears that he died either in Egypt, or in the desert; otherwise in the exodus he must be one hundred and forty years old, in the entrance into Canaan one hundred and eighty years old (Lapide, Bonfrerius); which age no one was attaining at that time (Bonfrerius). Therefore, he was a man of war in Egypt, and under the Kings of Egypt, before the persecution began against the Hebrews, Exodus 1, in the battles of the Ephraimites (against the Philistines [Bonfrerius]), who are related to have been slain, 1 Chronicles 7:21 (Lapide, Bonfrerius).
He was a man of war; he, that is, Machir, had given great proof of his valour in his generation, (though the particular history be not mentioned,) and his posterity were no degenerate sons, but had his valiant blood still running in their veins.
[And he had possession of Gilead and Bashan] Gilead was both a man, and a mountain or region; but neither took its name from the other: not the mountain, etc., from the man, for before the birth of Gilead thus the mountain was called, Genesis 31:48; nor the man from the mountain, etc., for this Gilead was born in Egypt; unless one should attribute this name to the inspiration of God, because his posterity was going to inhabit the region of Gilead. Moreover, the region of Gilead is taken either broadly, for that entire region on the other side of Jordan, especially for that part which fell to the Gadites and Manassites; or strictly, for that part of it which is closer to mount Gilead Eastward. But that part is called Bashan which is closer to Jordan (Bonfrerius). Gilead and Bashan; that is, partly; it is a Synecdoche (Junius and Malvenda): for the other part of Gilead had fallen to the Gadites, and the other part of Bashan had fallen to the Reubenites, as it is shown from Joshua 13:30, 31 (Malvenda). Now, Gilead is said to have had this possession, not because he himself held it, but rather his sons and grandsons (Menochius). He obtained this inheritance, because he was the first-born, and a man of war (Munster).
Gilead and Bashan, that is, part of those countries; for part of them was also given to the Reubenites, and part to the Gadites, as appears from Joshua 13:30, 31. This may be added as a reason, either, 1. Why he got those places from the Amorites; or, 2. Why they were allotted to him or his posterity, because this was a frontier country, and the outworks to the land of Canaan, and therefore required such valiant persons to defend it.
 Hebrew: וַיְהִ֤י הַגּוֹרָל֙ לְמַטֵּ֣ה מְנַשֶּׁ֔ה כִּי־ה֖וּא בְּכ֣וֹר יוֹסֵ֑ף לְמָכִיר֩ בְּכ֙וֹר מְנַשֶּׁ֜ה אֲבִ֣י הַגִּלְעָ֗ד כִּ֣י ה֤וּא הָיָה֙ אִ֣ישׁ מִלְחָמָ֔ה וַֽיְהִי־ל֖וֹ הַגִּלְעָ֥ד וְהַבָּשָֽׁן׃
 Joshua 17:1a: “There was also a lot for the tribe of Manasseh; for (כִּי) he was the firstborn of Joseph…”
 Hebrew: אֲבִ֣י הַגִּלְעָ֗ד.
 Hebrew: אִ֣ישׁ מִלְחָמָ֔ה.