Possible meanings are 1) Paul is quoting what the Corinthians had written. Alternate translation: "you wrote, 'It is good for a man not to touch a woman.'" or 2) Paul is saying what he really thinks. Alternate translation: "my answer is that yes, it is good for a man not to touch a woman."
Possible meanings are 1) "touch a woman" is a euphemism for having sexual relations. Alternate translation: "not to have sexual relations with his wife for a while" or 2) "touch a woman" is a metonym for marry. Alternate translation: "not to marry"