Sayvidina Abu Dharr (RA) narrated : I went into the mosque after sunset. The Prophet (SAW) was already seated there. He asked me, “0 Abu Dharr, do you know where this (sun) goes?” I said, Allah and His Messenger know best.” He said, “It goes to seek permission to make prostration and it is given permission, as though it is said to it, Rise from where you have come. So it rises from its west.” And he recited 'That is determined for it.' This is the recital of Abdullah ibn Mas’ud.
[Bukhari 3199, Muslim 159]
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