John Calvin Commentary Psalms 91:12

"They shall bear thee up in their hands, Lest thou dash thy foot against a stone." — Psalms 91:12 (ASV)

They shall bear thee upon their hands. He gives us a still higher idea of the guardianship of the angels, informing us that they not only watch so that no evil should befall us, and are alert to provide assistance, but also bear up our steps with their hands, to prevent us from stumbling in our course.

If we were to judge indeed by mere appearances, the children of God are far from being carried high in their journey in this way; they often labor and pant with exertion, occasionally they stagger and fall, and it is with a struggle that they advance in their course. But since, in the midst of all this weakness, it is only by God's unique help that they are preserved every moment from falling and from being destroyed, we should not wonder that the Psalmist speaks in such exalted terms of the assistance they receive through the ministry of angels.

Moreover, we could never surmount the serious obstacles Satan opposes to our prayers, unless God were to bear us up in the way described here. Let anyone combine the two considerations mentioned—our own utter weakness on the one hand, and on the other, the roughness, the difficulties, the thorns that beset our way, and also the stupidity that characterizes our hearts, and the subtlety of the evil one in laying snares for our destruction—and he will see that the Psalmist's language is not hyperbole, and that we could not proceed one step if the angels did not bear us up in their hands in a way beyond the ordinary course of nature.

Our frequent stumbling is due to our own fault in departing from him who is our head and leader. And though God allows us to stumble and fall in this way to convince us how weak we are in ourselves, yet, since he does not permit us to be crushed or completely overwhelmed, it is, even then, virtually as if he put his hand under us and bore us up.