2 Corinthians 13:12

This was customary with both Jews and Persians, as we learn from Xenophon and Herodotus, and with other oriental nations. And in process of time, from the custom of common life, it was introduced into ecclesiastial assemblies. The ancients were in the habit before they began their meal to embrace each other, to manifest by that sign their mutual cordiality and friendship; then they contributed their alms, that they might give a substantial proof of what was represented by their kiss of charity. (Pastorini)