John Wesley on Revelation 9:15

And the four angels were loosed, who were prepared - By loosing them, as well as by their strength and rage. To kill the third part of men - That is, an immense number of them. For the hour, and day, and month, and year - All this agrees with the slaughter which the Saracens made for a long time after Mahomet's death. And with the number of angels let loose agrees the number of their first and most eminent caliphs. These were Ali, Abubeker, Omar, and Osman. Mahomet named Ali, his cousin and son - in - law, for his successor; but he was soon worked out by the rest, till they severally died, and so made room for him. They succeeded each other, and each destroyed innumerable multitudes of men. There are in a prophetic Com. Years. Com. Days. Hour 8 Day 196 in all 212 years. Month 15 318 Year 196 117