The title of this watercolor image by J. Tissot comes from a directive Jesus Christ gave His apostles when He sent them to preach the Gospel.
"And into whatsoever city or town you shall enter, inquire who in it is worthy, and there abide till you go thence. And when you come into the house, salute it, saying: Peace be to this house. And if that house be worthy, your peace shall come upon it; but if it be not worthy, your peace shall return to you." — Matthew 10:11-13