The story of Abraham in the first reading is a lesson on being hospitable. It invites us to re-read the passage to find how many gracious things Abraham did for his guests. Here is my count.
First, he was not too self-absorbed to notice men who needed a welcome. Second he ran to greet them. Third, he said they would be doing him a favor by stopping. Fourth, he had them rest in the shade. Fifth, he brought water to soothe their feet.
Sixth, he had Sarah prepare an abundance of bread, and seventh he had a servant roast a whole steer. Eighth he had curds and milk prepared. Ninth, he waited on the guests himself. (Father Corry always did that with our guests.)
Tenth, while his wife laughed at the notion of them bearing a son in their nineties, he would not dispute with guests. Our reading cuts off before telling us the eleventh nice thing Abraham did for his guests: he accompanied them on their way, as though it pained him to see the last of them.