Isaac of Nineveh

Divine providence surrounds all persons at all times, but it is not visible except to those who have purified their souls of sin and think about God at all times. To these it is luminously revealed at that time; because when they have undergone great temptations for the sake of truth, then they receive the faculty to perceive sensibly as if with eyes of flesh also when necessary, even palpably, according to the kind and cause of the temptation, as if for greater encouragement.So it was with Jacob and Joshua son of Nun, Hananiah and his companions, Peter and others to whom the form of a man appeared to encourage them and to console their faith.