Цитата к Берешит 18:1

And this is "and Hashem appeared to him at the terebinths of Mamre", meaning, that thought Avraham was on the bed, the essence of his sitting really was on the upper worlds, and this is hinted to in "in the heat of the day", meaning, in the heat of holiness and clinging to God, since the heat and the clinging of the upper world is called 'day', as we explained. And this is easy to understand.

The verse states: And the Lord appeared to him. This expression is not written any [other] place [perhaps he means to say any other place before Abraham was circumcised]. And we can say [to explain this,] that there was no appearance of God in the world until Abraham accepted the covenant [of circumcision]. But from when he accepted the covenant, God appeared in the world. It comes out that that the Holy One, blessed be He, appears in the world on account of Abraham. And this is [the meaning of] And the Lord appeared to him. That is that he brought the sojourning of the Lord into this world. And then Isaac was born and then Jacob was born. [For] the forefathers are the chariot of the supernal Lights that appeared in the world, that being a sign for [their] children. The forefathers are a marker and a sign for the children, that we should learn from them and see how much effort the forefathers expended in this world and what level they reached with their efforts. And that is the teaching to their children, that every Jew should expend effort and toil, each one according to his place and makeup. [Then] they will certainly reach a high level. For the entire Torah teaches us how to be a Jew.