Hadhrat Umar-bin-Abdul Aziz (Rahmatullah alaih) appointed a person as governor of a province. Somebody remarked that this person had held the same post under Hajjaj-bin-Yusuf (the notorious blood shedder) also. Hadhrat Umar bin Abdul Aziz (Rahmatullah alaih) immediately issued orders of his dismissal. The man protested:

I had been with Hajjaj only for a very short time." To this, the Khalifa replied:

"His company for a day or even less is sufficient to render a man unfit for public service."

"A man is known by the company he keeps." The company of pious people leaves an imperceptible impression of piety on the character, and likewise evil company has its evil influence. That is why association with bad people is always discouraged. Even the company of animals is not without its own effect. The Prophet (Sallallaho alaihe wasallam) said:

"Pride and arrogance are prone to be found in those who own camels and horses, while meekness and humility characterise those who tend sheep and goats."

The Prophet (Sallallaho alaihe wasallam) is reported to have said:

"A person who associates with a pious man is like one who sits with a musk-seller. Even if he does not receive any musk from the latter still the pleasant smell would be a source of pleasure to him. But bad company may be likened to a furnace; a man sitting near one cannot escape the smoke and the fumes, even if a spark does not fall on him."