Holy Prophet (peace be upon him) among many of his prophecies has mentioned, in one Hadith a prophecy which many of us have seen fulfilled in our life time. More than 1400 years ago, our beloved master, Muhammad (peace be upon him) made a prophecy in the following words:
Abdullah bin Amar (RA) relates that the Holy Prophet (peace be upon him) said “Surely things will happen to my people as happened earlier to Israelites, they will resemble each other like one shoe in a pair resembles the other to the extent that if anyone among the Israelites has openly committed adultery to his mother there will be some who will do this in my Ummah as well, verily the Israelites were divided into 72 sections but my people will be divided into 73 sections, all of them will be in the fire except one.” The companions asked, ‘Who are they O Messenger of Allah,’ Holy Prophet (peace be upon him) said, “They are those who will be like me and my companions.“
In this hadith there are quite a few things to be noted. Firstly, it mentions the resemblance of Muslim Ummah with the Israelites (i.e. Jews). In another hadith  this resemblance is mentioned in the words that as among the Jews a prophet was raised in every century among Muslims a reformer will be raised and as among the Jews at the end of the chain of prophets a Messiah was raised a Messiah will be raised among Muslims. Among Jews there were 12 tribes each divided into six sects making a total of 72 sects at the time when the Messiah (i.e. Jesus, AS) was sent to Israelites (A full list of the Jewish sects at the time of Jesus, peace be upon him, is included in Appendix I). After the appearance of the Messiah among Jewish people the list of sects increased considerably. So while talking about 73 divisions among Muslims and taking into account the resemblances of Muslim Ummah to the Jewish people mentioned in both of the above tradition, it appears that these two ahadith relate to the time of the Promised Messiah (AS).
Having mentioned the resemblance of his Ummah with Jews, and division of the Ummah into 73 sections, Holy Prophet (peace be upon him) mentions that all will be in fire except one. Meaning 72 sects will be in fire while one will be safe. When asked who the safe ones will be, Holy Prophet (peace be upon him) replied “They are those who will be like me and my companions” indicating that remaining 72 will resemble Israelites while only one will resemble him and his companions. Having said that we have to understand that there ought to be a way to separate one Jama’at from 72. Thus there should be some method by which two sets of sections among Muslim Ummah will be formed and in one set there will be only one Jama’at (to which Holy Prophet, peace be upon him, referred to as resembling him and his companions) while the other set will contain 72 sects which will resemble Jews. To go any further we have to establish here three things. Firstly that there were at one time 73 sections of Muslims. Secondly they formed two sets on containing one Jama’at and the other one containing 72 sects. Thirdly the set containing one Jama’at consisted of the followers of a claimant of Messiahship. The third condition has to be fulfilled because, as I have established above, we are referring to the time of the Promised Messiah (AS), only the followers of Messiah can form a Jama’at which resembles Holy Prophet (peace be upon him) and his companions (RA). To establish that the above mentioned three conditions were fulfilled, I shall present here my translation of a portion of an editorial published in Urdu in Pakistani daily newspaper “Nawai Waqt” .
“One of the special importance of this decision has been that on it the consensus of Ummah has been in substantially correct manner. Throughout the history of Islam, such an overwhelming complete consensus has never been reached on any important topic. Other than the big religious scholars, holders of Shar’a, all the political leaders and political leaders of each group have agreed on this consensus. Other than these, all sufia karam, aarifeen Billah, the leaders of Tassawaf and practices had complete agreement. Excluding Qadianis all the rest of 72 sects which are considered to be of Muslims, agreed and are happy on the solution of this affair. Among the leaders of the nation and a’maideen, there does not appear to be any group which does not have a joyous attitude towards this decision. Nation should take a notice of this.”
And that was not the only newspaper which testified the number to be 72 following is another testimony of an English newspaper published from U.K. .
“By a constitutional amendment the National Assembly has stripped half a million members of the Ahmadiyya community of their religious status as Moslems. The excommunication of such a large number claiming to be Moslems by a political institution is a unique event in the 1400 years of the history of Islam. The burden of taking the measure fell on the National Assembly because Islam rejects priesthood and the Moslems, although divided into 72 sects, do not have a church or a pope. Religious edicts handed down by muftis or religious scholars are not binding on any individual or body of Moslems.”
Clearly, according to these newspapers there existed 73 sections in Islam, one Jama’at-e-Ahmadiyya and the rest of the 72 (A full list of the sects in Islam is included in Appendix II). The rest of the 72 sects were unanimous and happy and formed a party (a set) excluding the one (the other set) from Islam. Although they all had fatwas declaring one another to be kafirs, when it came to the question of Ahmadi Muslims they were all united so that there remains no doubt as to the identity of 72 and one making a total of 73. I have already established that Jews had 72 sects at the time of Messiah, so this hadith would be reflecting the time of Messiah among Muslim Ummah, which all Muslims today believe is also the time of the appearance of the Mahdi.