He will go before him in the spirit and power of Elijah, 'to turn the hearts of the fathers to the children,' and the disobedient to the wisdom of the just; to make ready a people prepared for the Lord."
"Elijah comes to defile and to cleanse (i.e. to pronounce what things are clean or unclean), and to remove afar off, and to bring near (i.e. to determine what families are legitimate or illegitimate). R. Simeon says, "to compose differences"; and the wise men say, neither to remove, nor to bring near, but לעשות שלום, "to make peace" in the world; as it is said, "behold, I send unto you Elijah the prophet", c. "and he shall turn the heart of the fathers", c.''