3:81 And Allah took a covenant from the prophets:
“For what I have given you of the Book and wisdom,
then a messenger will come to you authenticating what is with you.
You will believe in him and support him.”
He said: “Do you testify, and agree to this burden?”
They said: “We testify.”
He said: “Then bear witness, and I am with you bearing witness.”
Messenger in verse 3:81 is referring to a Generic messenger
We have to remember that there is no mention of any particular messenger or prophet in this ayat by name. The Sunnis believe it refers to Prophet Muhammad, the followers of Rashad Khalifa believe it refers to him.
However, the nominative indefinite noun ‘rasulun’ (a messenger) is not restricted ==> to any particular messenger <== even Jibril.
This ayat can be used as a reference to a ‘generic messenger’, to ‘any particular messenger’ or group of messengers hence indicating the ‘idea’/concept’.
This can clearly be seen in the following verse:
“And when there came to them a messenger/ rasulun from Allah, confirming what was with them, a party of the people of the Book threw away the Book of Allah behind their backs, as if they did not know!” 2/101
Thus in this particular ayat the ‘rasulun’ in 2/101 is not a reference to any particular messenger just like Surah 3/81 but rather, it refers to a ‘generic’ messenger.
This is clearly attested if one consults the previous verses and its context. The context refers to a people that kept breaking their covenant after ratifying them by virtue of the fact that when a messenger came to confirm the message as in 3/81, they rejected him.
To me its clear that the ‘rasulun’ in 3/81 is also not a reference to any particular messenger in much the same way as the ‘rasulun’ in 2/101.
Also recognize the plurality of messengers in verse in Surah Yasin Surah 26 when two messengers were sent and were then strengthened with a third 36/14.
“When We (first) sent to them two (messengers), but they denied both of them. So We strengthened them with a third and they said, “Truly, we have been sent to you as messengers.” 36/14
Also we have to pay much attention to the covenant in 3/81which is usually misunderstood as being taken ‘with ==> the prophets’. <==
However, upon further research this unwarranted from the context of the verse ayat. Hence, imagine this ayat that is mistakenly believed was only taken with the Prophets…but now what does the next ayat say?
“Then whoever turns away after this, they are perverted transgressors / wrongdoers / disobedient (fasiqun)” 3/82
Can any one of us imagine or believe that the prophets would have had any inclination to turn away from their covenants after ratifying them only to be potentially classed as ‘fasiqs’? Nah, of course not.
Again, unwarranted indeed because the covenant in 3/81 was through:
1) The Prophets
2) Also with their respective people and communities who ratified the covenant.
So we know that each prophet took a covenant with his community, that if hence,
1) a messenger or
2) messengers (the singular can be used to denote a generic ‘messenger(s) came to them confirming what was with them, then they would be expected to render him / them help.
This also ties in with verse 7/157 where the Ahlul Kitab/People of the Book are expected to ‘help’ (wa’nasaruhu) the Prophet Muhammad due to a prior covenant (3/81).
So we read that this covenant was ratified by their ancestors and to which they have also borne allegiance by virtue of them accepting their forefather’s faith as truth.
“… So those who believe in him, honour him, help him (wanasarahu), and follow the light which is sent down with him, it is they who will prosper / be successful.” 7/157
To me Surah 3/81 indicates that all Prophets made a covenant with their respective communities and Prophet Muhammad who was given the Revelation/The Qur’an from Jibril would not have been an exception nor is he cited as an exception. Remember Jibril was a messenger to the Prophet Muhammad.
“O you Children of Adam! whenever there come to you messengers from among you, rehearsing My verses (ayati) to you, those who are righteous and mend (their lives), on them shall be no fear nor shall they grieve” 7/35
So Surah 3/81 to me refers to a generic messenger/messenger (s). Its the idea/notion/concept that Allah gives us not a particular person.