Rev. renders the two aorists strictly: did touch, and I perceived, with reference to Jesus' knowledge of the touch at the moment it was applied.
Virtue (δύναμιν)
Rev., power. The evangelists use the word frequently of miracles - mighty works. It is used here in the sense of virtue, according to its use by naturalists and physicians. Still, too much stress must not be laid upon it as a mark of Luke's professional accuracy, as Dean Plumptre in “The Expositor,” iv., 139; since Mark uses it in his narrative of the same incident, and in the same sense (Mar 5:30).