إِذَا الشَّمْسُ كُوِّرَ‌تْ (When the sun will be folded up...81:1) The word kawwara is derived from Takwir which denotes for the sun 'to lose its light'.1 Sayyidna Hasan Basri (رح) has attached this interpretation to it. Another sense of the word is 'to cause to fall'. Rabi` Ibn Khaitham assigns the following interpretation to this verse: The Sun will be thrown into the ocean, and as a result of its heat the entire ocean will turn into fire. The two interpretations are not contradictory. They may be reconciled thus: first, its light will be put off and then it may be thrown into the ocean. Sahih of Bukhari records from Sayyidna Abu Huharirah ؓ that the Holy Prophet ﷺ said that on the Day of Resurrection the Sun and the Moon would be thrown into the ocean. Musnad of Bazzar has the addition that they will be thrown into Hell. Ibn Abi Hatim, Ibn Abid-Dunya and Abush-Shaikh stated that on the Day of Resurrection Allah will throw the Sun, the Moon and all stars into the ocean. Then a violent wind will blow over them, as a result of which the entire ocean will turn into fire. Thus it is correct to say that the Sun and the Moon will be put into the ocean. It is likewise correct to say that they will be put into Hell, because the entire ocean at that time will have been turned into Hell. [ Derived from Mazhari and Qurtubi ]

(1) Another meaning of Takwir is 'to fold', and the translation in the text is based on this meaning. The sense of folding the sun is that its function will come to an end, and it will lose its light. As such, it comes to mean same thing as mentioned in first interpretation. Muhammad Taqi Usmani