Jamieson, Fausset and Brown on 2 Corinthians 6:17

17. Quoted from Is 52:11, with the freedom of one inspired, who gives variations sanctioned by the Holy Spirit.

be ye separate--"be separated" (Ho 4:17).

touch not the unclean thing--rather, "anything unclean" (2Co 7:1; Mi 2:10). Touching is more polluting, as implying participation, than seeing.

receive you--The Greek implies, "to myself"; as persons heretofore out of doors, but now admitted within (2Co 5:1-10). With this accords the clause, "Come out from among them," namely, so as to be received to me. So Eze 20:41, "I will accept you"; and Zep 3:19, "gather her that was driven out." "The intercourse of believers with the world should resemble that of angels, who, when they have been sent a message from heaven, discharge their office with the utmost promptness, and joyfully fly back home to the presence of God" (1Co 7:31; 5:9, 10).