وَمَا لَكُمْ لَا تُوْمِنُونَ بِاللَّهِ
وَالرَّسُولُ يَدْعُوكُمْ لِتُوْمِنُوا بِرَبِّكُمْ
And what is the matter with you that you believe not in Allah! While the Messenger invites you to believe in your Lord;
meaning,
what prevents you from believing, while the Messenger is among you calling you to faith and bringing forward clear proofs and evidences that affirm the truth of what he brought you?
And we have reported the Hadith through different routes in the beginning of the explanation on the chapter on Faith in Sahih Al-Bukhari, wherein one day the Messenger of Allah said to his Companions,
أَيُّ الْمُوْمِنِينَ أَعْجَبُ إِلَيْكُمْ إِيمَانًا
Who do you consider among the believers as having the most amazing faith?
They said, "The angels."
He said,
وَمَا لَهُمْ لَا يُوْمِنُونَ وَهُمْ عِنْدَ رَبِّهِمْ
And what prevents them from believing when they are with their Lord?
They said, "Then the Prophets."
He said,
وَمَالَهُمْ لَا يُوْمِنُونَ وَالْوَحْيُ يَنْزِلُ عَلَيْهِمْ
What prevents them from believing when the revelation comes down to them?
They said, "Then us."
He said,
وَمَالَكُمْ لَا تُوْمِنُونَ وَأَنَا بَيْنَ أَظْهُرِكُمْ وَلكِنْ أَعْجَبُ الْمُوْمِنِينَ إِيمَانًا قَوْمٌ يَجِييُونَ بَعْدَكُمْ يَجِدُونَ صُحُفًا يُوْمِنُونَ بِمَا فِيهَا
What prevents you from believing, when I am amongst you Actually, the believers who have the most amazing faith, are some people who will come after you; they will find pages that they will believe in.
We mentioned a part of this Hadith when explaining Allah's statement in Surah Al-Baqarah,
الَّذِينَ يُوْمِنُونَ بِالْغَيْبِ
(who believe in the Ghayb (unseen), (2;3)
Allah's statement,
وَقَدْ أَخَذَ مِيثَاقَكُمْ
and He has indeed taken your covenant,
is similar to another of His statements,
وَاذْكُرُواْ نِعْمَةَ اللَّهِ عَلَيْكُمْ وَمِيثَـقَهُ الَّذِى وَاثَقَكُم بِهِ إِذْ قُلْتُمْ سَمِعْنَا وَأَطَعْنَا
And remember Allah's favor to you and His covenant with which He bound you when you said;"We hear and we obey." (5;7),
which refers to giving the pledge of allegiance to the Prophet.
Ibn Jarir said that the covenant mentioned here, is that taken from mankind, when they were still in Adam's loin.
This is also the opinion of Mujahid, and Allah knows best.
إِن كُنتُم مُّوْمِنِينَ
if you are real believers.
Allah said