‘Peace be to this house!’”
εἰς ἣν δ’ ἂν εἰσέλθητε οἰκίαν, πρῶτον λέγετε Εἰρήνη τῷ οἴκῳ τούτῳ.
Luke said that Jesus told the 70 disciples that whatever house they entered (εἰς ἣν δ’ ἂν εἰσέλθητε οἰκίαν), they were first to say (πρῶτον λέγετε) “Peace be to this house (Εἰρήνη τῷ οἴκῳ τούτῳ)”. The early followers of Jesus were to bring peace not strife, but this was a standard greeting anyway. Matthew, 10:12 had Jesus give these same simple instructions to the 12 apostles. As they went into a house, they were to greet or pay respects to the people in the house. This was only common sense. You had to respect, greet, and bring peace to the people in whose house you entered. How do you greet people?