Revelation 11:5

And if any man would hurt them, &c. These two verses seem to signify both the miracles which God many times wrought by the prayers of his martyrs, as he had done frequently in the time of Elias [Elijah] and the exemplary punishments with which from time to time he chastised those by whom they were persecuted, and that he will do the like by Henoch [Enoch] and Elias, when they shall come. (Witham) --- In this and the following verse are expressed the miraculous powers with which the two witnesses will be invested. These powers will be necessary to enable them to prove the truth of their doctrine. Every messenger who appears with a commission from God, is always furnished with means to prove it. Thus our Saviour and his apostles worked miracles in testimony of the Christian religion. And in the Old Testament, Elias convicted the false prophets by a miracle. See 3 Kings xviii. Every new teacher consequently, who comes destitute of this sanction, can claim no credit, but is only to be considered as an imposter. (Pastorini)