[18].Surah Al-Kahf [The Cave]:Ayat 21

 
Ayat 21. And thus We made their case known to the people, that they might know that the Promise of Allah is true, and that there can be no doubt about the Hour. (Remember) when they (the people of the city) disputed among themselves about their case, they said: "Construct a building over them, their Lord knows best about them," (then) those who won their point said (most probably the disbelievers): "We verily shall build a place of worship over them."

[Tafseer] Thus: in this way, by these means, i.e., by the sending out of one of the Sleepers with the old money to the town to buy provisions. His old-fashioned dress, appearance, and speech, and the old uncurrent money which he brought, at once drew the attention of people to him . When they learnt his story, they realized that Allah, Who can protect His servants thus and raise them up from sleep after such a long time, has power to raise up men for the Resurrection, and that His promise of goodness and mercy to those who serve Him is true and was exemplified in this striking way. On the other hand, to the men of the Cave themselves, it became clear that Allah can change the situation before we are aware, and our hope in Him is not futile, and that even when we are on the brink of despair, a revolution is surely working in the world before the world itself realizes it. The perversity of man is such that as soon as ever a glimpse of truth becomes manifest, men fall into controversies about it. The Sleepers could not judge about the duration of their stay in the Cave, but they wisely left the matter and attended to the urgent business of their lives. The townsfolk could not agree as to the significance of the event; they fell to discussing immaterial details. What sort of a memorial should they raise? a house or a place of worship or a tablet? The place of worship was built. But the real significance was missed until explained in the Quran. 

Hazrat Abu Hurairah (May Allah be pleased with him) reported: Messenger of Allah [SAWW](PBUH) said, "Remember more often the destroyer of pleasures - death.'' [At-Tirmidhi Hadith # 2307].

 

Lesson : as mentioned above in Surah Al-Kahf Ayat 21. "Promise of Allah is true, and that there can be no doubt about the Hour." Being heedful and talking about death checks man from being lost in the worldly pleasures and seductions. We are, therefore, supposed to remember death frequently and to avoid remaining indifferent to post-death affairs and occurrences.