The non Ahmadis quote that the Holy Prophet Muhammad(saw) has stated that if there was to have been a prophet after him it would have been Umar Bin Khattab(ra)
Imam Tirmidhi has recorded this Hadith and he has said that,‘This Hadith is unreliable.”
Character of Mishrah:
Ibni Habban has declared Mishrah bin Ha‘an as being unreliable and that his narrations are not deemed as being trustworthy. And the truth is that wherever he is the sole-narrator of a Hadith, such a Hadith should be abandoned. Ibni Dawood states that this narrator was a part of that army which laid siege upon Hadrat ‘Abdullah bin Zubair and threw rocks upon the Ka‘bah with catapults.”Tahzibut-Tahzib, Volume 10, p. 155, Mizanul-I‘itidal, Volume 2, p. 477, Volume 3, p. 172
Imam Shaukani : In the chain of narrators, there are two who are worthy of being abandoned, and they are ‘Abdullah bin Waqidi and Mishrah bin Ha‘an.”((Al-Fawa’idul-Majmu‘ati fil-Hadithil-Maudu‘ah, Muhammadi Press Lahore, p. 113)
Even Imam Suyuti (ra) said its weak : Jami‘us-Saghir, Babul-Lam, Volume 2, p. 131
Now its sad that you take this one unauthentic hadith to try to say that there is no prophet and ignore all the prophecies of Muhammad(saw). If you take this hadith to be authentic understand that badi can also refer to immediately after. As Ahmadis we don’t take one hadith and ignore the rest, you need to see everything Nabi(saw) said. He prophesied of a latter day messiah who would be a prophet, who is Ahmad(As), also. So what does this hadith mean then if Muhammad(saw) prophesied about a prophet? It refers to an immediate prophet after Muhammad(Saw) then it would be Umar(ra) (if we take it to be authentic) both ways we know the latter day messiah had to come as a prophet and has indeed come.
Another narration some Non Ahmadis try to quote is “Had I not been raised as a prophet verily you would have been in my stead O Umar”
This makes it clear that Umar(ra) had the qualities of Prophethood and that he would a prophet if Muhammad(saw) was not appointed. We Ahmadis accept all ahadith and do not take one and ignore the rest which the non Ahmadis sadly do when coming to these ahadith. It is also interesting that they use these ahadith to close prophethood when they themselves know of the prophesies of Muhammad(saw) prophesising a prophet and await a prophet themselves.