They answering said, John the Baptist,.... This was the opinion of some who thought that he was risen from the dead, as in Luk 9:7.
but some say Elias; the prophet, and the Tishbite; who according to the Jewish notion, was to be the forerunner of the Messiah, so in Luk 7:8.
and others say: that one of the old prophets is risen again; thus were they divided in their sentiments about him. See Gill on Luk 9:8