Pratimoksha of the Dharmaguptakas 1.29

1.29

「若比丘！往來彼此媒嫁，持男意語女，持女意語男，若為成婦事，若為私通事，乃至須臾頃，僧伽婆尸沙。

If a monk, in his journeyings, busy himself as a matchmaker between this one and another, and being the messenger of a man, talk with the woman on these points, or being the messenger of a woman, talk with the man on this subject; and if he thus complete arrangements so that there be intercourse between the two, whether for marriage or the occasion only, let him be suspended.