As for the meaning of Ghayb here, the Salaf have different explanations of it, all of which are correct, indicating the same general meaning. For instance, Abu Ja`far Ar-Razi quoted Ar-Rabi` bin Anas, reporting from Abu Al-`Aliyah about Allah's statement, i
((Those who) have faith in the Ghayb), "They believe in Allah, His angels, Books, Messengers, the Last Day, His Paradise, Fire and in the meeting with Him. They also believe in life after death and in Resurrection. All of this is the Ghayb.'' Qatadah bin Di`amah said similarly.
Sa`id bin Mansur reported from `Abdur-Rahman bin Yazid who said, "We were sitting with `Abdullah bin Mas`ud when we mentioned the Companions of the Prophet and their deeds being superior to our deeds. `Abdullah said, `The matter of Muhammad was clear for those who saw him. By He other than Whom there is no God, no person will ever acquire a better type of faith than believing in Al-Ghayb.' He then recited,
﴿الم - ذَلِكَ الْكِتَابُ لاَ رَيْبَ فِيهِ هُدًى لِّلْمُتَّقِينَ الَّذِينَ يُؤْمِنُونَ بِالْغَيْبِ﴾
(Alif Lam Mim. This is the Book, wherein there is no doubt, a guidance for the Muttaqin. Those who believe in the Ghayb), until,
(the successful). '' Ibn Abi Hatim, Ibn Marduwyah and Al-Hakim, in his Mustadrak, recorded this Hadith. Al-Hakim commented that this Hadith is authentic and that the Two Shaykhs - Al-Bukhari and Muslim - did not collect it, although it meets their criteria.
Ahmad recorded a Hadith with similar meaning from Ibn Muhayriz who said: I said to Abu Jumu`ah, "Narrate a Hadith for us that you heard from the Messenger of Allah.'' He said, "Yes. I will narrate a good Hadith for you. Once we had lunch with the Messenger of Allah . Abu `Ubaydah, who was with us, said, `O Messenger of Allah! Are people better than us We embraced Islam with you and performed Jihad with you.' He said,
«نَعَمْ قَوْمٌ مِنْ بَعْدِكُمْ يُؤْمِنُونَ بِي وَلَمْ يَرَوْنِي»
(Yes, those who will come after you, who will believe in me although they did not see me.)''
This Hadith has another route collected by Abu Bakr bin Marduwyah in his Tafsir, from Salih bin Jubayr who said: `Abu Jumu`ah Al-Ansari, the Companion of the Messenger of Allah , came to Bayt Al-Maqdis (Jerusalem) to perform the prayer. Raja' bin Haywah was with us, so when Abu Jumu`ah finished, we went out to greet him. When he was about to leave, he said, "You have a gift and a right. I will narrate a Hadith for you that I heard from the Messenger of Allah. '' We said, "Do so, and may Allah grant you mercy.'' He said, "We were with the Messenger of Allah, ten people including Mu`adh bin Jabal. We said, "O Messenger of Allah! Are there people who will acquire greater rewards than us We believed in Allah and followed you.' He said,
«مَا يَمْنَعُكُمْ مِنْ ذَلِكَ وَرَسُولُ اللهِ بَيْنَ أَظْهُرِكُمْ يَأْتِيكُمْ بِالْوَحْيِ مِنَ السَّمَاءِ، بَلْ قَوْمٌ بَعْدَكُمْ يَأْتِيهِمْ كِتَابٌ مِنْ بَيْنِ لَوْحَيْنِ يُؤْمِنُونَ بِهِ وَيَعْمَلُونَ بِمَا فِيهِ، أُولٰئِكَ أَعْظَمُ مِنْكُمْ أَجْرًا مَرَّتَيْن»
(What prevents you from doing so, while the Messenger of Allah is among you, bringing you the revelation from heaven There are people who will come after you and who will be given a book between two covers (the Qur'an), and they will believe in it and implement its commands. They have a greater reward than you, even twice as much.)''
﴿وَيُقِيمُونَ الصَّلٰوةَ وَمِمَّا رَزَقْنَـهُمْ يُنفِقُونَ﴾
(And perform Salah, and spend out of what we have provided for them)