Measure your foodgrains before selling them.

This hadith teaches us that when we buy foodgrains, we should not sell them until they have been measured. This is an important lesson to remember as it ensures fairness in the marketplace. If someone buys a certain amount of foodgrains but then sells them without measuring them first, they may end up selling more than what was originally bought and this would be unfair to the buyer. Therefore, this hadith reminds us to always measure our foodgrains before selling them so that everyone involved can be sure of the exact amount being sold or bought.