‘And he and the men who were with him ate and drank and remained all night, and in the morning they rose up and he said, “Send me away to my master”.'
Now that his mission is accomplished the steward accepts the hospitality of the house. He and his men are well entertained and finally go to rest. But the steward is aware that his master is eagerly awaiting word and next day insists that he must return immediately. Had Abraham himself come such haste would have been considered unseemly, but coming from a servant it was acceptable.