YUSUFALI: Truly thou wilt die (one day), and truly they (too) will die (one day).
PICKTHAL: Lo! thou wilt die, and lo! they will die;
SHAKIR: Surely you shall die and they (too) shall surely die. Surah 039:030
YUSUFALI: Say: "I am no bringer of new-fangled doctrine among the messengers, nor do I know what will be done with me or with you. I follow but that which is revealed to me by inspiration; I am but a Warner open and clear."
PICKTHAL: Say: I am no new thing among the messengers (of Allah), nor know I what will be done with me or with you. I do but follow that which is inspired in me, and I am but a plain warner.
SHAKIR: Say: I am not the first of the messengers, and I do not know what will be done with me or with you: I do not follow anything but that which is revealed to me, and I am nothing but a plain warner. Surah 046:009
Muhammad could not say for certain what would become of him and his followers after death. However he was sure of this, that the unbeliever, those who did not revert (covert) to Islam would die and go to hell.
YUSUFALI: Who, then, doth more wrong than one who utters a lie concerning Allah, and rejects the Truth when it comes to him; is there not in Hell an abode for blasphemers?
PICKTHAL: And who doth greater wrong than he who telleth a lie against Allah, and denieth the truth when it reacheth him? Will not the home of disbelievers be in hell?
SHAKIR: Who is then more unjust than he who utters a lie against Allah and (he who) gives the lie to the truth when it comes to him; is there not in hell an abode for the unbelievers? Surah 039:032
The reason that Muhammad did not know where he would be after death is that what Allah requires good deeds, to enter paradise. The Qur'anic verse below applies to Muslims then as well as today. Like Muhammad, today's Muslim is never sure if he or she has done enough good deeds to enter paradise. The only exception is to die while participating in violent Jihad.
YUSUFALI: And to all are (assigned) degrees according to the deeds which they (have done), and in order that (Allah) may recompense their deeds, and no injustice be done to them.
PICKTHAL: And for all there will be ranks from what they do, that He may pay them for their deeds; and they will not be wronged.
SHAKIR: And for all are degrees according to what they did, and that He may pay them back fully their deeds and they shall not be wronged. Surah 046.019
YUSUFALI: Muhammad is no more than a messenger: many Were the messenger that passed away before him. If he died or were slain, will ye then Turn back on your heels? If any did turn back on his heels, not the least harm will he do to Allah; but Allah (on the other hand) will swiftly reward those who (serve Him) with gratitude.
PICKTHAL: Muhammad is but a messenger, messengers (the like of whom) have passed away before him. Will it be that, when he dieth or is slain, ye will turn back on your heels? He who turneth back on his heels doth no hurt to Allah, and Allah will reward the thankful.
SHAKIR: And Muhammad is no more than a messenger; the messengers have already passed away before him; if then he dies or is killed will you turn back upon your heels? And whoever turns back upon his heels!s, he will by no means do harm to Allah in the least and Allah will reward the grateful. Surah 003.144
Whoever shall call upon the name of the Lord (Jesus Christ) shall be saved. (from their sins)
Romans 10:9