one of the shaykhs wished to discipline some of his companions who had committed many sins, so he said:

“My son, I enjoin upon you just one quality, so uphold it for my sake. For now, I ask nothing else of you: adhere to truthfulness, and beware of lying.”

He threatened him with severe punishment for lying. When he committed himself to this, truthfulness led him to all other goodness and restrained him from his former ways, for the wicked person knows no bounds in lying.