He heard these two jokes when he was a kid in Jordan. There were many little fruit vendors back then, and there were a lot of beggars back then too.
“A poor man wants to sell fruits on a cart to make some money. So a beggar came to this guy asking for something from his cart for free. The guy looked at him, and gave him a small watermelon. So the beggar said, ‘The smallest one? I thought you were going to give me a bigger one. You know what, you will teach people to not beg from you.’”
“A beggar goes to a butcher, and asks for a free piece of meat. The butcher goes and cuts a piece for him. The beggar then responds ‘You’re not going to cook it for me?’”
I found these jokes funny because they switch out the expected expression of gratitude with the opposite: an expression of ingratitude. Because they occupy the space between the expected and unexpected, they get the listeners’ attention, and strike them as funny. Because these jokes sound similar to the English saying “Beggars aren’t choosers,” they could have been used as a build-up to an equivalent saying in Arabic (or just the English saying).