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
deu 3:1CONQUEST OF OG, KING OF BASHAN. (Deu. 3:1-20)
we turned, and went up the way to Bashan--Bashan ("fruitful" or "flat"), now El-Bottein, lay situated to the north of Gilead and extended as far as Hermon. It was a rugged mountainous country, valuable however for its rich and luxuriant pastures.
Og the king of Bashan came out against us--Without provocation, he rushed to attack the Israelites, either disliking the presence of such dangerous neighbors, or burning to avenge the overthrow of his friends and allies.
deu 3:2The Lord said unto me, Fear him not: for I will deliver him, and all his people, and his land, into thy hand--Og's gigantic appearance and the formidable array of forces he will bring to the field, need not discourage you; for, belonging to a doomed race, he is destined to share the fate of Sihon [Num 21:25].
deu 3:3Argob was the capital of a district in Bashan of the same name, which, together with other fifty-nine cities in the same province, were conspicuous for their lofty and fortified walls. It was a war of extermination. Houses and cities were razed to the ground; all classes of people were put to the sword; and nothing was saved but the cattle, of which an immense amount fell as spoil into the hands of the conquerors. Thus, the two Amorite kings and the entire population of their dominions were extirpated. The whole country east of the Jordan--first upland downs from the torrent of the Arnon on the south to that of the Jabbok on the north; next the high mountain tract of Gilead and Bashan from the deep ravine of Jabbok--became the possession of the Israelites.
deu 3:9Hermon--now Jebel-Es-Sheick--the majestic hill on which the long and elevated range of Anti-Lebanon terminates. Its summit and the ridges on its sides are almost constantly covered with snow. It is not so much one high mountain as a whole cluster of mountain peaks, the highest in Palestine. According to the survey taken by the English Government Engineers in 1840, they were about 9376 feet above the sea. Being a mountain chain, it is no wonder that it should have received different names at different points from the different tribes which lay along the base--all of them designating extraordinary height: Hermon, the lofty peak; "Sirion," or in an abbreviated form "Sion" (Deu 4:48), the upraised, glittering; "Shenir," the glittering breastplate of ice.
deu 3:11only Og king of Bashan remained of the remnant of giants--literally, "of Rephaim." He was not the last giant, but the only living remnant in the trans-jordanic country (Jos 15:14), of a certain gigantic race, supposed to be the most ancient inhabitants of Palestine.
behold, his bedstead was a bedstead of iron--Although beds in the East are with the common people nothing more than a simple mattress, bedsteads are not unknown. They are in use among the great, who prefer them of iron or other metals, not only for strength and durability, but for the prevention of the troublesome insects which in warm climates commonly infest wood. Taking the cubit at half a yard, the bedstead of Og would measure thirteen and a half feet, so that as beds are usually a little larger than the persons who occupy them, the stature of the Amorite king may be estimated at about eleven or twelve feet; or he might have caused his bed to be made much larger than was necessary, as Alexander the Great did for each of his foot soldiers, to impress the Indians with an idea of the extraordinary strength and stature of his men [LE CLERC]. But how did Og's bedstead come to be in Rabbath, of the children of Ammon? In answer to this question, it has been said, that Og had, on the eve of engagement, conveyed it to Rabbath for safety. Or it may be that Moses, after capturing it, may have sold it to the Ammonites, who had kept it as an antiquarian curiosity till their capital was sacked in the time of David. This is a most unlikely supposition, and besides renders it necessary to consider the latter clause of this verse as an interpolation inserted long after the time of Moses. To avoid this, some eminent critics take the Hebrew word rendered "bedstead" to mean "coffin." They think that the king of Bashan having been wounded in battle, fled to Rabbath, where he died and was buried; hence the dimensions of his "coffin" are given [DATHE, ROOS].
deu 3:12this land, which we possessed at that time, from Aroer . . . gave I unto the Reubenites and to the Gadites--The whole territory occupied by Sihon was parcelled out among the pastoral tribes of Reuben and Gad. It extended from the north bank of the Arnon to the south half of mount Gilead--a small mountain ridge, now called Djelaad, about six or seven miles south of the Jabbok, and eight miles in length. The northern portion of Gilead and the rich pasture lands of Bashan--a large province, consisting, with the exception of a few bleak and rocky spots, of strong and fertile soil--was assigned to the half-tribe of Manasseh.
deu 3:14Jair the son of Manasseh took all the country of Argob--The original inhabitants of the province north of Bashan, comprising sixty cities (Deu 3:4), not having been extirpated along with Og, this people were afterwards brought into subjection by the energy of Jair. This chief, of the tribe of Manasseh, in accordance with the pastoral habits of his people, called these newly acquired towns by a name which signifies "Jair's Bedouin Villages of Tents."
unto this day--This remark must evidently have been introduced by Ezra, or some of the pious men who arranged and collected the books of Moses.
deu 3:15I gave Gilead unto Machir--It was only the half of Gilead (Deu 3:12-13) which was given to the descendants of Machir, who was now dead.
deu 3:16from Gilead--that is, not the mountainous region, but the town Ramoth-gilead,
even unto the river Arnon half the valley--The word "valley" signifies a wady, either filled with water or dry, as the Arnon is in summer, and thus the proper rendering of the passage will be--"even to the half or middle of the river Arnon" (compare Jos 12:2). This prudent arrangement of the boundaries was evidently made to prevent all disputes between the adjacent tribes about the exclusive right to the water.
deu 3:25I pray thee, let me go over, and see the good land that is beyond Jordan, that goodly mountain, and Lebanon--The natural and very earnest wish of Moses to be allowed to cross the Jordan was founded on the idea that the divine threatening might be conditional and revertible. "That goodly mountain" is supposed by Jewish writers to have pointed to the hill on which the temple was to be built (Deu 12:5; Exo 15:2). But biblical scholars now, generally, render the words--"that goodly mountain, even Lebanon," and consider it to be mentioned as typifying the beauty of Palestine, of which hills and mountains were so prominent a feature.
deu 3:26speak no more unto me of this matter--that is, My decree is unalterable.