Translation of the verse 26 from Surah Al-Mulk : Number of verses 30 - - page 563 - Part 29.
Say (O Muhammad SAW): "The knowledge (of its exact time) is with Allah only, and I am only a plain warner."
Say, "The knowledge is only with Allah, and I am only a clear warner."
(67:26) Say: 'Allah alone knows about that; and I am no more than a plain warner.' *36
*36) That is, "This I know that it will certainly come, and knowing this much only is enough for warning the people before its actual occurrence. As for the question when it will actually come, the knowledge of it is with Allah, not with me, and there is no need of this knowledge for administering the warning. This can be better understood by an example. As to the exact time when a person will die, it is only known to Allah; however, all know that everyone has to die one day. Our this knowledge is enough that we may warn a heedless friend of ours that he should look after himself and his interests before death. For this warning it is not necessary to know the exact day on which he will die.
Source : Al-Mulk Verse 26: Say, "The knowledge is only with Allah, and I am only a clear warner."