Genesis 18:22

And the men turned their faces from thence
From the place to which Abraham brought them on; these were only two of them, for the third continued with Abraham: and went towards Sodom;
and are the two angels said to come thither at evening, ( Genesis 19:1 ) : but Abraham stood yet before the Lord;
before the third person, whom Abraham now began to know more clearly; he stood before him with all reverence and humility, to hear what he had further to say to him, as well as to say something to him himself; he stood "yet", he continued to stand after the departure of the two angels that were gone to Sodom. Onkelos and Jonathan paraphrase it,

``he ministered in prayer before the Lord.''