One day David asked his wife to go to the market and buy a mosquito net. His wife went to a shop and asked the shopkeeper to show her the best quality net.
The shopkeeper showing her a very good net said, "This is the best quality which you won't be able to find elsewhere. Not even a single mosquito can pass through it."
Mrs. David refused to but the net. When the shopkeeper asked the reason, she said, "If a mosquito can't pass through it, then how will we pass through it." Then she returned home and narrated the whole matter to her husband.
Hearing the whole matter, David laughed at his wife's foolishness.