Al-Hikmah (wisdom, good manners and high character) which Allah has revealed in the Qur'an.
"And your Lord has decreed that you worship none but Him. And that you be dutiful to your parents. If one of them or both of them attain old age in your life, say not to them a word of disrespect, nor shout at them but address them in terms of honour." Ayah 23: Surah Al Isra'
"And lower to them the wing of submission and humility through mercy, and say: "My Lord! Bestow on them Your Mercy as they did bring me up when I was young." Ayah 24: Surah Al Isra'
"And give to the kinsman his due and to the Miskin*[1] (needy) and to the wayfarer. But spend not wastefully (your wealth) in the manner of a spendthrift.*[2] Ayah 26: Surah Al Isra'
"And if you turn away from them (kindred, needy, wayfarer, whom We have ordered you to give their rights, but if you have no money at the time they ask you for it) and you are awaiting a mercy from your Lord for which you hope, then, speak to them a soft, kind word (i.e. Allah will give me and I shall give you). Ayah 28: Surah Al Isra'
"And follow not (O man, i.e. say not or do not or witness not) that of which you have no knowledge*[3]. Verily the hearing, and the sight, and the heart of each of those ones will be questioned (By Allah). Ayah 36: Surah Al Isra'
"And walk not on the earth with conceit and arrogance. Verily you can neither rend nor penetrate the earth nor can you attain a stature like the mountains in height." Ayah 37: Surah Al Isra'
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*[1]Al Miskin (the needy) is not the one who goes round the people and asks them for a mouthful or two (of meals) or a date or two, but Al-Miskin is that who has not enough (money) to satisfy his needs and whose condition is not known to others, that others may give him something in charity, and who does not beg of people." [Sahih Al-Bukhari, 2/1479(O.P/557)].
*[2]You have to follow a middle course in your spendings - neither a miser nor a spendthrift, and not to be like those who spend in the disobedience of Allah and His Messenger (Peace be upon him).
*[3]You have no knowledge: e.g. one's saying: "I have seen," while in fact he has not seen, or "I have heard", while he has not heard.