There is not to be upon the Prophet any discomfort concerning that which Allah has imposed upon him. [This is] the established way of Allah with those [prophets] who have passed on before

     There is not to be upon the Prophet any discomfort concerning that which Allah has imposed upon him. [This is] the established way of Allah with those [prophets] who have passed on before. And ever is the command of Allah a destiny decreed. [Allah praises] those who convey the messages of Allah and fear Him and do not fear anyone but Allah. And sufficient is Allah as Accountant. Muhammad is not the father of [any] one of your men, but [he is] the Messenger of Allah and seal [i.e., last] of the prophets. And ever is Allah, of all things, Knowing. 

THE QUR'AN, al-Ahzab 33:38-40