Don Quixote Volume 1, Chapter 21
As they continue on their journey it begins to lightly rain. Don Quijote spots a rider with golden object on his head. Don Quijote believes it to be none other than the famous golden helmet of Mambrino. It is actually a basin that belongs to a barber on his way to a small village (that has no barber), who placed the basin on his head when it began to rain. But, alas for the poor barber, Don Quijote has knighted him and placed him on a dapple-gray horse and without further ado charges at the barber while brandishing his lance and crying out for him to surrender or defend himself.
The barber drops off his donkey to avoid the attack and runs away leaving his basin. Sancho hands the basin to Don Quijote commenting on its excellence as a basin. Don Quijote admits that it is not unlike a basin, but that it is still the helmet of Mambrino that has, at some point, been melted down and reshaped.
Sancho, looking for some spoils of war for himself, manages to convince Don Quijote (who is a bit murky on some of the finer rules of knight errantry) to let him trade his donkey's harness and bridle for the fancy ones on the barber's mount. (It later becomes evident that he snatched the saddlebag also.) In this chapter Sancho pays lip service to Don Quijote's directive -- that the squire talk less -- but he actually talks just as much and continues to be impudent. They continue on and Don Quijote reassures Sancho that great rewards await them both, but now is a time for Don Quijote to prove himself worthy. Sancho makes plans that when he becomes a count he will have his very own barber to follow him about and keep him well shaved. Don Quijote says he will be the first count to have such a thing, but why not?