To cast away honesty upon a foul slut were to put good meat into an unclean dish.
(29-30)
Touchstone is saying that chastity (the good meat) is wasted on an ugly prostitute (the unclean dish). Audrey’s only defense to this line is that she is not a slut or prostitute.
In any event, Touchstone still wants to marry Audrey even though he makes a little speech about cuckoldry being the fate of the married man. A cuckold is a man whose wife is having an affair with someone else. During the Middle Ages there existed a superstitious belief that a cuckold would grow horns upon his forehead. Touchstone predicts that he will grow horns upon his head: that is, he will become a cuckold after he is married. Despite that, he still feels that being a cuckold is better than being an unmarried bachelor.
Touchstone has arranged for Sir Oliver Martext, a country minister, to perform the wedding ceremony; and Martext appears on stage immediately after Touchstone’s speech on cuckoldry (at line 52). Jacques, however, warns Touchstone that a marriage conducted by this country minister will not be legally binding: it will not be a legal marriage. Martext is not a licensed minister, apparently. Thus, his text or words will be marred or damaged. His words will be meaningless, and Touchstone and Audrey will not be really married.
Touchstone jokes that not being legally