When the spirit is suffocated from inner turmoil and taken up with various kinds of restlessness, having been deprived for the moment of any hope of human aid and turning totally to the Lord, an angel of the Lord descends near to it. In other words, the divine word descends to the aid of the servant and brushes aside the burning blazes of passion so that the heated darts of the enemy do not penetrate the inner citadel of our heart and the enemy cannot hold us in his fiery furnace. - "Commentary on Daniel 3.49–30"
When the soul is oppressed with tribulation and taken up with various vexations, having lost hope of human aid and turned with its whole heart to God, an angel of the Lord descends to it. That is to say, the supernatural being descends to the aid of the servant and dashes aside the fierce heat of the violent flames, that the fiery shafts of the enemy utterly fail to pierce the inner citadel of our heart and we escape being shut up in his fiery furnace.