Exodus 17:12

But Moses's hands were heavy,.... And hung down through weariness, holding up the rod first in one hand, and then in another, for so long a time; and thus sometimes, through infirmity, the best of men grow remiss in prayer, their hands are weak and hang flown through the corruptions of their hearts, the power of unbelief, the temptations of Satan, and want of immediate answers of prayer, or through long delays of it, and then the enemy gets an advantage over them:

and they took a stone, and put it under him, and he sat thereon; so that it seems not only that his hands were heavy, but he could not well stand on his feet any longer, being a corpulent man as well as in years, as Ben Gersom suggests; and therefore Aaron and Hur took a stone that lay on the mount for him to sit upon, where he might be raised as high, and be as well seen, as standing: this stone may be an emblem of Christ the stone of Israel, the foundation of his people, their prop and support, which sustains and upholds them, their Ebenezer, or stone of help in all their times of difficulty and distress:

and Aaron and Hur stayed up his hands, the one on the one side, and the other on the other side; the one was on his right, and the other on his left; and when the rod was in his right hand, he that was on that side held up that; and when it was in his left hand, he that was on the left side supported that: these may be an emblem of Christ, and of the Spirit of Christ, from whom the saints have their supports and assistance in prayer: Aaron the priest may represent Christ, from whose blood, righteousness, and sacrifice, and from whose advocacy, mediation, and intercession, the people of God receive much encouragement and strength in their addresses at the throne of grace: and Hur, who has his name from a word which signifies freedom and liberty, may be an emblem of the Holy Spirit of God; who helps the saints in prayer under all their infirmities, and makes intercession for them, by filling their hearts and mouths with arguments, and is a free spirit to them; by whom they are upheld, and where he is there is liberty, and a soul can come forth in prayer to God, and in the exercise of grace with freedom:

and his hands were steady until the going down of the sun; when the victory was decided in favour of Israel; this may denote steadiness of faith in prayer, the constant performance of it, and continuance in it as long as a man lives.