Ambrose of Milan
Catena Aurea · Matthäusevangelium 10
And into whatsoever city or town ye shall enter, enquire who in it is worthy; and there abide till ye go thence. And when ye come into an house, salute it. And if the house be worthy, let your peace eome upon it: but if it be not worthy, let your peace return to you. And whosoever shall not receive you, nor hear your words, when ye depart out of that house or eity, shake off the dust of your feet. Verily I say unto you, It shall be more tolerable for the land of Sodom and Gomorrha in the day of judgment, than for that city.
(in Luc. 9:5.) The Apostles are not to choose carelessly the house into which they enter, that they may have no cause for changing their lodging; the same caution is not enforced upon the entertainer,lest in choosing his guests, his hospitality should be diminished. When ye enter a house, salute it, saying, Peace be to this house.