Adam Clarke on John 11:21

If thou hadst been here, my brother had not died - Mary said the same words to him a little after, Joh 11:32, which proves that these sisters had not a complete knowledge of the omnipotence of Christ: they thought he could cure at hand, but not at a distance; or they thought that it was because he did not know of their brother's indisposition that he permitted him to die. In either of these cases it plainly appears they had not a proper notion of his divinity; and indeed the following verse proves that they considered him in no other light than that of a prophet. Query - Was it not proper that Christ should, in general, as much as might be, hide the knowledge of his divinity from those with whom he ordinarily lodged? Had they known him fully, would not the reverence and awe connected with such a knowledge have overwhelmed them?