Charles H. Spurgeon on Psalms 91:12

To carry them in their hands is a metaphor, and signifies a perfect execution of their custody, to have a special care of them, and therefore is rather expressed so, than carrying them on their shoulders. That which one carries on their hand they are sure to keep. The Spaniards have a proverb when they would signify eminent favour and friendship, `they carry him upon the palms of their hands, 'that is, they exceedingly love him, and diligently keep him. Lest thou dash thy foot against a stone. He persists in the metaphor: children often stumble and fall, unless they be led and carried in hands and arms. By stones are meant all difficulties, objections, perils, both to the outward and inward man, as Christ is said to take care of hairs and sparrows, that is, of every thing even to a hair. Now we know what this charge is, saving that Zanchy adds also the metaphor of schoolmasters, and says that we are poor rustic people, strangers; but being adopted into the household of God, he gives his most noble ministers, the angels, charge, first of our nursing and then of our education; when we are weaned, to instruct us, to admonish, to institute, to correct us, to comfort us, to defend us, to preserve us from all evil, and to provoke us to all good. And these angels, seeing we are so dear to God, that for our sakes he spared not his own Son, take this charge with all their hearts upon them, and omit nothing of their duty from our birth to the end of our life. Henry Lawrence, in "A Treatise of our Communion and Warre with Angells, "1646.