ספר בראשית

This is also the meaning of the Midrash (Baba ‎batra 16,) according to which Avraham wore a necklace ‎featuring a jewel around his neck that miraculously healed sick ‎people when they looked at it. According to this Midrash, ‎after Avraham died, G’d suspended this jewel in the solar orbit. ‎Rabbi Shimon, the author of that Midrash, used it as a ‎parable explaining how beneficial it was for a sick person to come ‎within the field of vision of Avraham. This was so important a ‎feature of Avraham’s personality that G’d could not allow it to die ‎with him, and He equipped the sun with therapeutic qualities.‎