Targum Pseudo-Jonathan on Genesis 18:2 gives the three visitors at Abraham's tent their heavenly job descriptions. They are angels in the likeness of men, the Targum says, and they have been sent from the necessity of three things — because it is not possible for a ministering angel to be sent for more than one purpose at a time.
One had come to announce that Sarah would bear a son. One had come to deliver Lot. One had come to overthrow Sedom and Amorah.
This is classical Jewish angelology in a single sentence. A malakh is a messenger, not a general-purpose servant. Each angel carries exactly one mission. The Torah's famous visit to Abraham is therefore not the arrival of one heavenly delegation but the arrival of three distinct missions that happen to overlap at one man's door.
And Abraham — ill from circumcision, sitting in the heat — runs to meet them. The verse is precise. He ran. He bowed himself to the ground. He did not wait to see which one carried his good news.
The Maggid hears the lesson in how Abraham receives heaven. He does not ask which guest is the important one. He does not ask which of them has brought word about Isaac. He hurries out and honors all three, because hospitality in Abraham's tent is not about sorting the messengers (Genesis 18:2). Later he will learn which angel carried which message. First, he runs. That is the covenant in action. Receive heaven before you audit it.