Nahj al-Balagha (Peak of Eloquence)

38. Amīr al-mu’minīn, peace be upon him, said to his son al-Ḥasan: O my son, learn four things and (a further) four things from me. Nothing will harm you if you practise them. That the richest of riches is intelligence; the biggest destitution is foolishness; the wildest wildness is vanity and the best achievement is goodness of the moral character. O my son, you should avoid making friends with a fool because he may intend to benefit you but may harm you; you should avoid making friends with a miser because he will run away from you when you need him most; you should avoid making friends with a sinful person because he will sell you for nought; and you should avoid making friends with a liar because he is like a mirage, making you feel far things near and near things far.