The name of this Sûrah has been taken from verse 9 “Do you think that the people of the cave (Al-Kahf) and engraved plate (Ar-Raqeem) were from among OUR strange Signs?” The meaning of this name means the Sûrah in which the word (al-Kahf) has mentioned.
Period of Revelation:
It is the start of those Sûrahs, which have been revealed in the third part of Makki period. We have divided the Makki life into four main stages; details have been given in the introduction of Sûrah Al-An’âm. According to that division -- the third period starts around 5 A. H. and goes until 10 A. H. The thing which distinguishes this period from the second period -- is that, in second period to suppress the Islamic Movement the Quraish mainly depended on ridiculing, threatening, tempting, raising objections and making false propagandas against the Prophet Muhammad sallallaahu ‘alayhi wa sallam and his followers. However, during the third period they used the weapons of persecution, cruelty, and economic pressure with full severity, so much so that a large number of the Muslims had to migrate to Habash, and rest of the Muslims along with Prophet Muhammad sallallaahu ‘alayhi wa sallam and his family were confined in the value of Shu’aib Abe Talib and a complete social and economic embargo was implemented against them. However, at that time there were two such personalities -- Abu Talib and Mother of All Muslims Hadrat Khadijah – because of their personal influence the two great families of Quraish were supporting Prophet Muhammad sallallaahu ‘alayhi wa sallam. In 10 A.H. they both died and this period ended and the fourth period started, in which the Muslims life was made miserable and as a last resort the Prophet Muhammad sallallaahu ‘alayhi wa sallam and all his Companions emigrated from Makkah.
It appears from the subject matter of the Sûrah Al-Kahf that it would have been revealed in the beginning of the third period when the persecution and opposition has reached to its limits but the migration to Habash had not yet taken place. The Muslims who were being persecuted at that time, the story of "Ashab-i-Kahf" (the Sleepers of the Cave) has been narrated to comfort and encourage them, and to make them aware that what former believers have done to save their Faith.
Subject and Theme:
This Sûrah has been revealed in order to answer the three questions of the Mushrikûn of Makkah, which they asked after consulting with the people of the Book, to test the Prophet Muhammad sallallaahu ‘alayhi wa sallam -- these were:
1) Who were "Ashab-i-Kahf” (the Sleepers of' the Cave)?
2) What is the reality of the story of Khidr? And
3) What is the story of Zul-Qarnain?
All the three stories were related to the history of the Christians and the Jews. These were not common in Hijaaz. This is why the people of the Book selected these questions to test whether the Prophet Muhammad sallallaahu ‘alayhi wa sallam has any unseen source of the knowledge or not. Allâh subhaana wa ta’aala, not only gave a complete answer to their questions through the Prophet Muhammad sallallaahu ‘alayhi wa sallam but also made use of the three stories to pin the circumstances which were going on at that time in Makkah between Islam and Kufr:
1. It was told about the Ashab-i-Kahf (Sleepers of the Cave) that they were the believers of the same Tauhid which Al-Qur’ân is presenting, and their condition was no different than the condition of the victimized Muslims of Makkah -- the oppressors of the sleepers of the Cave had behaved in the same way towards them as the disbelievers of the Quraish were behaving towards the Muslims. Then with the same story the Muslims have been taught that even if a Believer is ill-treated by a Kafir Cruel society and does not have any respite at all even then he/she should not bow down before falsehood -- but should set out all alone with complete Trust in Allâh subhaana wa ta’aala. Accordingly, the disbelievers of Makkah were also told that the story of the Sleepers of the Cave was a clear proof of the truth of the Hereafter. As Allâh subhaana wa ta’aala raised the sleepers of the cave after a long time in the same way, HE has the power to resurrect you after the death, which you are refusing to accept.
In this way the test questions of disbelievers were turned on them and then the same things were repeated at the end which are narrated in the beginning, that Tauhid and the Hereafter are the truth and it is for your own good to bring Faith in it. Mend your ways in accordance with them and live your life with the conviction of accountability to Allâh subhaana wa ta’aala. If you will not do so – your life will be ruined and whatever you have done will be wasted.