3. The solemn ratification of this promise: The Lord has sworn by his right hand, and by the arm of his strength, that he will do this for his people. God confirms it by an oath, that his people, who trust in him and his word, may have strong consolation, Heb. vi. 17, 18. And, since he can swear by no greater, he swears by himself, sometimes by his being (As I live, Ezek. xxxiii. 11), sometimes by his holiness (Ps. lxxxix. 35), here by his power, his right hand (which was lifted up in swearing, Deut. xxxii. 40), and his arm of power; for it is a great satisfaction to those who build their hopes on God's promise to be sure that what he has promised he is able to perform, Rom. iv. 21. To assure us of this he has sworn by his strength, pawning the reputation of his omnipotence upon it; if he do not do it, let it be said, It was because he could not, which the Egyptians shall never say (Num. xiv. 16) nor any other. It is the comfort of God's people that his power is engaged for them, his right hand, where the Mediator sits.