Chapter 18 of Genesis opens with one of the most intimate moments in the Torah, and Targum Pseudo-Jonathan gives it a medical detail the Hebrew leaves implicit.
The glory of the Lord — the Shekhinah, in the Aramaic idiom — was revealed to Abraham in the plains of Mamre. And he, being ill from the pain of circumcision, sat at the door of the tabernacle in the fervour of the day.
The Targum names the ache out loud. Abraham is ninety-nine. He circumcised himself in the previous chapter (Genesis 17:24). He is now recovering in the hottest part of the afternoon, propped up in the shade of his tent door, unable to do much more than sit.
And the Lord comes to visit.
The rabbis will later build an entire theology of bikkur cholim — visiting the sick — around this verse. If the Shekhinah itself came to Abraham's door while he was convalescing from a mitzvah, then showing up at the bedside of a sick neighbor is no minor gesture. It is imitation of God.
The Maggid notices the order. First the commandment. Then the cut. Then the pain. Then the visit (Genesis 18:1). Heaven does not bless Abraham with a new child and then send him to the knife. It sends him to the knife first, and shows up in person while the wound is still fresh. The covenant is not abstract. It hurts, and the Lord knows it hurts, and the Lord still shows up in the heat of the day to sit with a tired old man at his tent door.