And they turned and went up by the way of Bashan: and Og the king of Bashan went out against them, he, and all his people, to the battle at Edrei.

Wesley's Notes

21:33 Og - Who also was a king of the Amorites. And it may seem that Sihon and Og were the leaders or captains of two great colonies which came out of Canaan, and drove out the former inhabitants of these places. Bashan - A rich country, famous for its pastures and breed of cattle, and for its oaks.

Jamieson-Fausset-Brown Bible Commentary

33. they turned and went up by the way of Bashan-a name given to that district from the richness of the soil-now Batanea or El-Bottein-a hilly region east of the Jordan lying between the mountains of Hermon on the north and those of Gilead on the south.

Og-a giant, an Amoritish prince, who, having opposed the progress of the Israelites, was defeated.

Matthew Henry's Concise Commentary

21:21-35 Sihon went with his forces against Israel, out of his own borders, without provocation, and so ran upon his own ruin. The enemies of God's church often perish by the counsels they think most wisely taken. Og, king of Bashan, instead of being warned by the fate of his neighbours, to make peace with Israel, makes war with them, which proves in like manner his destruction. Wicked men do their utmost to secure themselves and their possessions against the judgments of God; but all in vain, when the day comes on which they must fall. God gave Israel success, while Moses was with them, that he might see the beginning of the glorious work, though he must not live to see it finished. This was, in comparison, but as the day of small things, yet it was an earnest of great things. We must prepare for fresh conflicts and enemies. We must make no peace or truce with the powers of darkness, nor even treat with them; nor should we expect any pause in our contest. But, trusting in God, and obeying his commands, we shall be more than conquerors over every enemy.