The Qur'aan was revealed at a certain time and in reference, in many cases, to a certain people or incident. It is sometimes easy for the reader to become complacent and to think of the Qur'aan in terms of referring just to something that happened, something bygone. He thereby closes his eyes unconsciously to the fact that the Qur'aan was not revealed only for a specific era or for a specific people. Instead it is the guidance for all of mankind until the Day of Judgement. It contains lessons that transcend the constraints of time and place. The reader must open his eyes and realise that the Qur'aan, although it refers to specific events, is laying down lessons and principles that are valid for all times and places.
Instead of thinking only about the event referred to, it is must more important for the reader to think about how the Quranic lesson is being manifested in front of his own eyes or is to be applied in his times.
This is not meant to downplay the importance of the science of asbaab an-nuzool (the study of the events leading up to a specific revelation). In many cases, the actual meaning or proper intent of a particular verse cannot be fully understood without looking to the verse's asbaab an-nuzool. But that does not mean that the verse itself or its ruling or lesson is restricted to only that occasion or only to those individuals to whom it was originally referring. If that were the case, then perhaps much of the Qur'aan would have no validity today. This important point is why scholars agree upon the maxim: the ruling is determined by the generality of the text and not by the particularity of the occasion of the ruling.
That the text of the Qur'aan was not to be confined by time and place was something well known to the scholars of tafseer throughout the ages. Whenever they turned to the Qur'aan, they found guidance for their own place and time because they realised that the lessons and rulings of the Qur'aan were not to be restricted to the time of the Companions رضي الله عنهم of the Prophet صلى الله عليه وسلم. This was clearly reflected in their commentaries of the Qur'aan. Salaahud-Deen Al-Khaalidi notes,
"Each and every generation of Muslims found in the text of the Qur'aan a discussion of what they were passing through and what would improve their lives as if the Qur'aan was being revealed at that moment in particular. Every one of the commentators of the Qur'aan started from the texts of the Qur'aan to develop and train his people and make their situation better. And from every commentary on the Qur'aan one can derive the level of culture and civilisation, customs, social life, level of belief and behaviour for the period in which the commentator lived. That commentary was a recording of the civilisation and history of that period. That was only the case because the texts of the Qur'aan were applicable to the time and place of the commentator and were directed to the people around him." 
Allaah سبحانه و تعالى states,
The dreams of the Prophets عليهم الصلاة والسلام were all true - which was a valuable support to the veracity of their message. Whether they were sleeping or awake, Shaytaan was not allowed to make them envision falsehood.
Sa'eed Ibn Jubayr رحمه الله reported that Ibn 'Abbaas رضي الله عنهما said: "The Prophets' dreams are part of revelation." 
Imaam Ahmad رحمه الله said: "The dreams of the Prophets عليهم الصلاة والسلام were part of revelation. Only ignorant individuals would belittle dreams and claim that they have no consequence." 
Dreams are, therefore, included in the meaning of the aayah:
The correct belief in tawheed (Islamic monotheism) does not mean that one simply recognises that there is a God or Creator. It goes beyond that to having the proper beliefs about that Creator and submitting to that Creator and God in all realms of life, either as an individual in his worship and behaviour or as a society.
Imaam Ibn Abil-'Izz al-Hanafi رحمه الله said: "Most of the soorahs in the Qur'aan are concerned with the two types of tawheed ; in fact, everysoorah in the Qur'aan [is concerned with tawheed]. The Qur'aan either reports about Allaah's Names and Attributes سبحانه و تعالى. This is the tawheedthat one must have knowledge about and that is reported. Or the Qur'aan calls to His worship, associating no partner with Him [in that worship] and abandoning any other idol other than Him. This is the tawheed of intention and will. Or the Qur'aan orders, prohibits or commands [His] obedience. These are essential aspects of tawheed and part of its completeness. Or the Qur'aan reports about how [Allaah سبحانه و تعالى] honours the people [who adhere to] tawheed and what He does for them in this world and what He graciously bestows upon them in the Hereafter. That is the reward for [adhering to] tawheed. Or [the Qur'aan] reports about the polytheists and how He treats them in this world and what kind of punishment that will receive in the end. That is the punishment for those who abandon the aspects of tawheed." 
Sayyid Qutb رحمه الله echoed that statement when he wrote: "Defining the real uloohiyyah  and clarifying its particular aspects of Lordship, Sustainer and Ruler, and defining uboodiyyah  and its limits that must not be trespassed, and going from all of that to mankind worshipping their true Lord, and recognising that Lordship, Sustaining and Ruling belong only to Him..  This is the main topic of the entire Qur'aan.. And what is beyond that is simply an explanation of what this great truth [tawheed] implies and requires in the life of humans, in every respect."