2 Corinthians 6:17

Wherefore come out from among them A combination of Isaiah 52:11 with Ezekiel 20:34. This passage must be read in conjunction with 1 Corinthians 5:10, and must be understood not of absolute separation, but of abstinence from any kind of intimacy. "Wherever union in the highest cannot be, wherever idem velle atque idem nolleis impossible, there friendship and intimate partnership must not be tried." Robertson.

and touch not the unclean thing The passage (see Isaiah 52:11) refers to the priests and Levites, and relates to the ceremonial defilement caused by contact with whatever was unclean. See for instance Leviticus 11:8; Leviticus 11:24; Leviticus 11:31-40; also Revelation 18:4.