Here's a great article detailing the proofs of Muhammad [saw's] Prophethood, enjoy 
:
The Significance of Miracles
The prophetic miracle (muʿjiza) is that which manifests the incapacity (ʿajz) of creation to bring its like… Its formal definition according to theologians is “the appearance of a matter that breaks the customary norm, at the hand of one claiming prophecy, upon being challenged by those in denial, in a manner that incapacitates them to bring its like.”
The way a miracle indicates the truthfulness of a prophet is that we realize it is purely an act of God Most High, the servant having no share in it at all, such as turning a staff into a snake or bringing the dead to life. When God Most High produces it immediately after the prophet’s statement, “If I am truthful in my claim to being Your messenger, then do such and such,” it serves as a confirmation for him by action. It is akin to God’s saying, “You are truthful.”…
Proofs That Muhammad was a True Prophet (peace and blessings be upon him)
Having understood the above, we will now establish proofs of the truthfulness of our Prophet Muhammad (upon whom be peace and greetings), as that is the basis of this whole discussion. According to us, then, that of the rest of the prophets (upon whom be peace) is affirmed by his informing us.
This evidence has two main components:
I. The Qur’an
The first is the Qur’an, which challenged all the eloquent speakers of the Arabs and non-Arabs to bring the like of it. They proved incapable of doing so, as God Most High states:
–“And if you are in doubt as to that which We have revealed to Our servant, then bring the like of one of its chapters,” (2:23) and He Most High also says,
–“Say: verily if all humans and jinn gathered to bring the like of this Qur’an, they would not bring the like of it, even if some of them supported others,” (17:88) and other Qur’anic verses.
So all proved incapable of bringing the like of it, since if they were able to do so they certainly would have, due to their zeal for disproving his claim and overcoming his proof. Had they done so, it would surely have been well-known and transmitted to us, just as the false claims and senseless jabber of Musaylima the Liar were transmitted.
Challenges and Responses
(a) If it is said: Perhaps being preoccupied with combat and careers prevented them from that.
We respond:
read on:
SeekersGuidance - The Truth of Islam, the Qur’an, & the Prophet Muhammad (Peace and Blessings Be Upon Him) - Answers
Please also see this related answer, by the esteemed scholar Shaykh Akram Abdul Wahhab: How Do We Know That the Qur’an is Inimitable and Thus From Allah
:The Significance of Miracles
The prophetic miracle (muʿjiza) is that which manifests the incapacity (ʿajz) of creation to bring its like… Its formal definition according to theologians is “the appearance of a matter that breaks the customary norm, at the hand of one claiming prophecy, upon being challenged by those in denial, in a manner that incapacitates them to bring its like.”
The way a miracle indicates the truthfulness of a prophet is that we realize it is purely an act of God Most High, the servant having no share in it at all, such as turning a staff into a snake or bringing the dead to life. When God Most High produces it immediately after the prophet’s statement, “If I am truthful in my claim to being Your messenger, then do such and such,” it serves as a confirmation for him by action. It is akin to God’s saying, “You are truthful.”…
Proofs That Muhammad was a True Prophet (peace and blessings be upon him)
Having understood the above, we will now establish proofs of the truthfulness of our Prophet Muhammad (upon whom be peace and greetings), as that is the basis of this whole discussion. According to us, then, that of the rest of the prophets (upon whom be peace) is affirmed by his informing us.
This evidence has two main components:
I. The Qur’an
The first is the Qur’an, which challenged all the eloquent speakers of the Arabs and non-Arabs to bring the like of it. They proved incapable of doing so, as God Most High states:
–“And if you are in doubt as to that which We have revealed to Our servant, then bring the like of one of its chapters,” (2:23) and He Most High also says,
–“Say: verily if all humans and jinn gathered to bring the like of this Qur’an, they would not bring the like of it, even if some of them supported others,” (17:88) and other Qur’anic verses.
So all proved incapable of bringing the like of it, since if they were able to do so they certainly would have, due to their zeal for disproving his claim and overcoming his proof. Had they done so, it would surely have been well-known and transmitted to us, just as the false claims and senseless jabber of Musaylima the Liar were transmitted.
Challenges and Responses
(a) If it is said: Perhaps being preoccupied with combat and careers prevented them from that.
We respond:
read on:
SeekersGuidance - The Truth of Islam, the Qur’an, & the Prophet Muhammad (Peace and Blessings Be Upon Him) - Answers
Please also see this related answer, by the esteemed scholar Shaykh Akram Abdul Wahhab: How Do We Know That the Qur’an is Inimitable and Thus From Allah