Some important lesson from khutbatu  al-wada':  

Beware of Shay'tan for the safety of your religion. He has lost all hope that he will ever be able to lead you astray in big things, so beware of following him in small things.

Listen to me in earnest, worship Allah, say your five daily prayers (Salah), fast during the month of Ramadan, and give your wealth in Zakat. Perform Hajj if you can afford to.

All mankind is from Adam and Eve, an Arab has no superiority over a non-Arab nor a non-Arab has any superiority over an Arab; also a white has no superiority over a black, nor a black has any superiority over a white - except by piety and good action. Learn that every Muslim is a brother to every Muslim and that the Muslims constitute one brotherhood.

Remember one day you will appear before Allah and answer for your deeds. So beware, do not stray from the path of righteousness after I am gone.

People, no prophet or apostle will come after me and no new faith will be born. Reason well therefore, O people, and understand words which I convey to you. I leave behind me two things, the Quran and the Sunnah (Hadisth), and if you follow these you will never go astray.

DavidC wrote: What is khutbatu al-wada'?

It's the Prophet's (may Allah bless him and grant him peace) last sermon/khutbah.

Ask and you shall receive...

This sermon was delivered on the Ninth Day of Dhul-Hijjah 10 A.H. in the 'Uranah valley of Mount Arafat' in Mecca.

After praising and thanking Allah the Prophet (May Allah's peace and blessings be upon him) said:

"O People, lend me an attentive ear, for I know not whether after this year I shall ever be amongst you again. Therefore listen to what I am saying very carefully and take these words to those who could not be present here today.

O People, just as you regard this month, this day, this city as Sacred, so regard the life and property of every Muslim as a sacred trust. Return the goods entrusted to you to their rightful owners. Hurt no one so that no one may hurt you. Remember that you will indeed meet your Lord, and that he will indeed reckon your deeds. Allah has forbidden you to take usury (interest), therefore all interest obligations shall henceforth be waived. Your capital is yours to keep. You will neither inflict nor suffer any inequity. Allah has judged that there shall be no interest and that all the interest due to Abbas ibn 'Abd'al Muttalib [the Prophet's uncle] be waived.

Every right arising out of homicide in pre-islamic days is henceforth waived and the first such right that i waive is that arising from the murder of Rabiah ibn al Harithibn.

O People, the unbelievers indulge in tampering with the calender in order to make permissible that which Allah forbade, and to forbid that which Allah has made permissible. With Allah the months are twelve in number. Four of them are holy, three of these are successive and one occurs singly between the months of Jumada and Shaban.

Beware of Satan, for the safety of your religion. He has lost all hope of that he will be able to lead you astray in big things, so beware of following him in small things.

O People, it is true that you have certain rights with regard to your women but they also have rights over you. Remember that you have taken them as your wives only under Allah's trust and with His permission. If they abide by your right, then to them belongs the right to be fed and clothed in kindness. Do treat your women well and be kind to them for they are your partners and committed helpers. And it is your right that they do not make friends with anyone of whom you do not approve, as well as never to be unchaste. O People, listen to me in earnest, worship Allah, say your five daily prayers, fast during the month of Ramadhan, and give your wealth in Zakat. Perform Hajj if you can afford to.

All mankind is from Adam and Eve, an Arab has no superiority over a non-Arab nor a non-Arab has any superiority over an Arab; also a white has no superiority over a black nor a black has any superiority over a white - except by piety and good action. Learn that every Muslim is a brother to every Muslim and that the Muslims constitute one brotherhood. Nothing shall be legitimate to a Muslim which belogs to a fellow Muslim unless it was given freely and willingly. Do not therefore do injustice to yourselves. Remember one day you will meet Allah and answer your deeds. So beware: do not stray from the path of righteousness after I am gone.

O People, no prophet or apostle will come after me, and no new faith will be born. Reason well, therefore, O People, and understand my words which I convey to you. I leave behind me two things, the Qur'an and my Sunnah and if you follow these you will never go astray.

All those who listen to me shall pass on my words to others and those to others again; and may the last ones understand my words better than those who listen to me directly. Be my witness, O Allah, that I have conveyed Your message to Your people."

DavidC, http://www.soundvision.com/info/hajj/lastsermon.asp - this site gives you a good intro about this hadith.

Also, if I'm not mistaken, this verse was also revealed on the day of the sermon:

"Today, those who are bent on denying the truth have lost all hope of [your ever forsaking] your religion: do not, then, hold them in awe, but stand in awe of Me.

Today have I perfected your religious law for you, and have bestowed upon you the full measure of My blessings, and willed that self-surrender unto Me shall be your religion." (5:3)