Chasidut for Bava Batra 32:1

‎“And Avraham had aged, advanced in years;" the Talmud ‎‎Baba batra 16 understands the word ‎בכל‎ as meaning that ‎Avraham had a “daughter” by the name of ‎בכל‎. Commenting ‎further on this, the Talmud in Chagigah 15 states that a ‎heavenly voice i.e. ‎בת קול‎ [instead of ‎בת כל‎ Ed.] was heard at ‎Mount Sinai calling the Israelites to penance with the exception ‎of Acher, (Elisha ben Avuya) turned apostate.
‎[The text in my edition of the Talmud does not mention the ‎location where this heavenly voice was heard, and it would not ‎make sense that it was Mount Sinai, as the occasion appears to ‎have been at least 50 years after destruction of the second ‎Temple. Ed.]
We need to examine the nature of this “voice” somewhat ‎more closely. Since, according to the Talmud, this ‎בת קול‎ appears ‎to have been a visual manifestation rather than something heard ‎with one’s ears, the statement is enigmatic. Apparently, the ‎Talmud refers to a message that a person hears or is supposed to ‎hear daily as if it were as real as a vision. The true call to do ‎‎teshuvah had originated at Sinai when the people had heard ‎G’d address them directly during the first and second ‎Commandment, until they were so overwhelmed that they feared ‎to die and begged Moses to be their interpreter of G’d’s words. ‎Mount Sinai had been referred to as Mount Chorev in Exodus 3,1 ‎when Moses had his first vision of G’d at the burning bush. On ‎that occasion he had “heard” the voice of G’d. The term ‎בת קול‎ ‎has become the name for a derivative of that first communication ‎to His people through Moses their leader and prophet ever since. ‎At the revelation at Mount Sinai several months later, it had ‎become so real that the people were described as “seeing” the ‎voice rather than as merely “hearing it. (Exodus 20,15) We have ‎explained that the term ‎בן‎ or ‎בת‎ describes the receiving of G’d’s ‎largesse, when it has originated from G’d directly through the ‎merits of the patriarch Avraham. Just as G’d had to “reduce ‎Himself” in terms of His pure spirituality, man has to reduce his ‎‎“physicality,” i.e. his dependence on physical comforts provided ‎by our world somewhat, in order to qualify for receiving these ‎communications from G’d. Each human being desirous of coming ‎closer to G’d by this means has to do so in accordance with the ‎spiritual level he is capable of. The word ‎בת‎ in the language of the ‎‎Mishnah, is the preface used when describing the measure ‎of certain liquids or dry matter that a container can hold. Its use ‎in that sense originates in Ezekiel 45,10. [It may be correct to ‎understand the term ‎בת קול‎ which is usually associated with post ‎Biblical times, when there was no more direct communication ‎with G’d through prophets or even through the urim ‎vetumim on the High Priest’s breast plate, as a prophetic ‎communication from G’d, but at arm’s length. Ed.]‎‎‎

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.‎