Rashi on Genesis 20:7/רש"י על בראשית כ׳:ז׳

1השב אשת האיש RESTORE THE MAN’S WIFE and do not think that she will be repulsive in his eyes and that he will not take her back or that he will hate you and will not pray for you

2כי נביא הוא FOR HE IS A PROPHET and he knows that you have not touched her (Genesis Rabbah 52:8); therefore—ויתפלל בעדך HE WILL PRAY FOR THEE.