Al-Ahnaf bin Kais, whose prudence was proverbial among the Arabs, used to say: 'I have followed three rules of conduct, which I now mention merely that the man of reflection may profit by my example--I never interfered between two parties unless invited by them to do so; I never went to the door of these people (meaning princes) unless sent for by them; and I never rose from my place to obtain a thing when all men were anxious to possess it.' IX. Abu Yazid Taifur al-Bastaimi, the famous ascetic, being asked how he had acquired his knowledge of the spiritual world, answered that it was by means of a hungry belly and naked body. He used to say: 'When you see a man possessing miraculous powers, so as even to mount into the air, let not that deceive you, but see if he observes God's commands and prohibitions, if he keeps within the bounds imposed by religion, and if he performs the duties which it prescribes.' X. Abul Aswad ad-Duwali, the inventor of grammar, in intelligence one of the most perfect of men, and in reason one of the most sagacious, was notorious for his avarice, and he used to say: 'If we listened to the demands made by the poor for our money, we should soon be worse off than they.' He said also to his sons: 'Strive not to rival Almighty God in generosity, for He is the most bountiful and the most glorious; had He pleased He would have given ample wealth to all men, so strive not to be generous lest you die of starvation.' It is also related that Abul Aswad had an attack of the palsy, and that he used to go to the market himself, though scarcely able to draw his legs after him, and yet he was rich, and possessed both male and female slaves. A person who knew this accosted him one day, and said: 'God has dispensed you from the necessity of moving about on your own business, why do you not remain seated at home?' To which he replied: 'No; I go in and out, and the eunuch says "He is coming," and the boy says "He is coming," whereas, were I to continue sitting in the house, the sheep would urine upon me without any person's preventing them.' XI.