Where in the Quran does it say that Muhammad was the last Prophet and Messenger of GOD?
Let us look at the following Noble Verse in the Noble Quran:
"Muhammad is not the father of any of your men, but (he is) the Apostle of God, and the Seal of the Prophets: and God has full knowledge of all things. (The Noble Quran, 33:40)"
Comments from the foot notes of the translation of Sheikh (Minister) Abdullah Yusuf Ali; may Allah Almighty rest his soul and make Heaven his final destiny: "When a document is sealed, it is complete, and there can be no further addition. The Holy Prophet Muhammad closed the long line of Messengers. Allah's teaching is and will always be continuous, but there has been and will be no Prophet after Muhammad. The later ages will want thinkers and reformers, not Prophets. This is not an arbitrary matter. It is a decree full of knowledge and wisdom, 'for Allah has full knowledge of all things.'"
In the above Noble Verse we see Allah Almighty clearly Saying that Prophet Muhammad peace be upon him is the last Prophet (Messenger) sent by Allah Almighty to Mankind. In Arabic, the words "Prophet (Nabi)", and "Messenger (Rasul)" could and would mean the same thing. This means that Allah Almighty in the above Noble Verse said that Prophet Muhammad peace be upon him is the last Messenger and Prophet of GOD Almighty. The following Saying from our beloved Prophet peace be upon him will further prove it for us:
"In My Ummah (Islamic Nation), there shall be born Thirty Grand Liars (Dajjals), each of whom will claim to be a prophet, But I am the Last Prophet; there is No Prophet after Me. (Abu Dawood Vol 2 p. 228; Tirmidhi Vol 2 p.45)" [1]
"Narrated Abu Huraira: The Prophet said, 'The Israelis used to be ruled and guided by prophets: Whenever a prophet died, another would take over his place. There will be no prophet after me, but there will be Caliphs who will increase in number.' The people asked, 'O Allah's Apostle! What do you order us (to do)?' He said, 'Obey the one who will be given the pledge of allegiance first. Fulfil their (i.e. the Caliphs) rights, for Allah will ask them about (any shortcoming) in ruling those Allah has put under their guardianship.' (Translation of Sahih Bukhari, Virtues and Merits of the Prophet (peace be upon him) and his Companions, Volume 4, Book 56, Number 661)"
"Narrated Sad: Allah's Apostle set out for Tabuk. appointing 'Ali as his deputy (in Medina). 'Ali said, 'Do you want to leave me with the children and women?' The Prophet said, 'Will you not be pleased that you will be to me like Aaron to Moses? But there will be no prophet after me.' (Translation of Sahih Bukhari, Book 59, Military Expeditions led by the Prophet (peace be upon him) (Al-Maghaazi), Volume 5, Number 700)"
"Narrated Ubaida: Ali said (to the people of 'Iraq), "Judge as you used to judge, for I hate differences (and I do my best ) till the people unite as one group, or I die as my companions have died." And narrated Sad that the Prophet said to 'Ali, 'Will you not be pleased from this that you are to me like Aaron was to Moses?' (Translation of Sahih Bukhari, Book 57, Companions of the Prophet, Volume 5, Number 56)"
"Sa'd b. Abi Waqqas reported that Allah's Messenger (may peace be upon him) left 'Ali b. Abi Talib behind him (as he proceeded) to the expedition of Tabuk, whereupon he ('Ali) said: Allah's Messenger, are you leaving me behind amongst women 4nd children? Thereupon he (the Holy Prophet) said: Aren't you satisfied with being unto me what Aaron was unto Moses but with this exception that there would be no prophet after me. (Translation of Sahih Muslim, Book 31, The Book Pertaining to the Merits of the Companions (Allah Be Pleased With Them) of the Holy Prophet (May Peace Be Upon Him) (Kitab Al-Fada'il Al-Sahabah), Number 5914)"
"Sa'd reported Allah's Apostle (may peace be upon him) as saying to 'Ali: Aren't you satisfied with being unto me what Aaron was unto Moses? (Translation of Sahih Muslim, Book 31, The Book Pertaining to the Merits of the Companions (Allah Be Pleased With Them) of the Holy Prophet (May Peace Be Upon Him) (Kitab Al-Fada'il Al-Sahabah), Number 5916)"
"Narrated AbuHurayrah: The Prophet (peace_be_upon_him) said: There is no prophet between me and him, that is, Jesus (peace_be_upon_him). He will descent (to the earth). When you see him, recognise him: a man of medium height, reddish fair, wearing two light yellow garments, looking as if drops were falling down from his head though it will not be wet. He will fight the people for the cause of Islam. He will break the cross, kill swine, and abolish jizyah. Allah will perish all religions except Islam. He will destroy the Antichrist (Dajjal) and will live on the earth for forty years and then he will die. The Muslims will pray over him. (Translation of Sunan Abu-Dawud, Book 37, Battles (Kitab Al-Malahim), Number 4310)"
In the above Sayings (Hadiths) of our beloved Prophet Muhammad peace be upon him, we see several things:
1- The People of Israel used to be ruled and guided by Prophets from Allah Almighty, and Muhammad peace be upon him is the last Prophet and Messenger. No Messenger of Allah will come after him. Only Caliphs (Disciples) will come after him, and the Muslims must follow them.
2- He compared himself and his cousin and forth Disciple Ali bin-Abi Talib with Moses and his brother Aaron peace be upon all of them.
3- He used the word "prophet" for himself and as an expression for Moses peace be upon him. Moses and Muhammad peace be upon them are both Prophets and Messengers from Allah Almighty. Moses peace be upon him did not make predictions before. He only brought the Torah (the Law) to the People of Israel. Jesus and Muhammad peace be upon them on the other hand made predictions (prophecies) that were inspired by Allah Almighty. Yet, Moses and the other Messengers of Allah Almighty were referred to as "Prophets". That's because in Arabic as I mentioned above, the words "Messenger (Rasul)" and "Prophet (Nabi)" would and could mean the same thing.
4- Ali may Allah Almighty be pleased with him and honor his face (for refusing to bow to idols) is not sacred in Islam, because Prophet Muhammad peace be upon him told him that he is like Aaron to Moses to him, meaning they are like brothers, but Muhammad also told him that no more Messengers from Allah Almighty will come after him. This makes Ali not sacred in Islam, but very well respected.
5- Prophet Jesus came before Prophet Muhammad and will come after him peace be upon both of them. Prophet Muhammad peace be upon him made it clear that no new Prophet or Messenger will come after him. Only Jesus peace be upon him will. He will come and destroy the Antichrist, the Dajjal.
Further sites to research:
Prophet Muhammad peace be upon him in Islam.
Prophet Muhammad peace be upon him in the Bible.