Doth not even nature itself teach you
By nature is either meant, the law and light of nature, reason in man, common sense, or rather custom, which is second nature; and which, in this case, must be restrained to the Greeks and Jews; for though among the Grecians the men cut their hair, and did not suffer it to grow long, as also did the Jews, yet there were many nations F11 who did not, even at that time, observe such a rule or custom; but as the Jews and Greeks were the persons chiefly, if not solely, known to the Corinthians, the apostle signifies, that the usages of these people might direct and inform them in this matter:
that if a man have long hair it is a shame unto him;
he looks unmanly and womanish, and exposes himself to ridicule and contempt.