[Machine] I said, "O Messenger of Allah, I have placed a white thread and a black thread under my pillow, but I cannot distinguish between them." He said, "You have a wide bedspread, and that night is part of the day, as Allah says, 'And eat and drink until the white thread of dawn becomes distinct to you from the black thread. Then complete the fast until the night.' And do not approach them while you are in seclusion in the mosques. These are the limits set by Allah, so do not come near them.' Thus Allah makes clear His signs to the people that they may fear Him."
قُلْتُ يَا رَسُولَ اللَّهِ لَقَدْ جَعَلْتُ تَحْتَ وِسَادَتِي خَيْطًا أَبْيَضَ وَخَيْطًا أَسْوَدَ فَمَا تَبَيَّنَ لِي شَيْءٌ قَالَ «إِنَّكَ لَعَرِيضُ الْوِسَادِ وَإِنَّمَا ذَلِكَ اللَّيْلُ مِنَ النَّهَارِ فِي قَوْلِهِ تَعَالَى» {وَكُلُوا وَاشْرَبُوا حَتَّى يَتَبَيَّنَ لَكُمُ الْخَيْطُ الْأَبْيَضُ مِنَ الْخَيْطِ الْأَسْوَدِ مِنَ الْفَجْرِ ثُمَّ أَتِّمُّوا الصِّيَامَ إِلَى اللَّيْلِ وَلَا تُبَاشِرُوهُنَّ وَأَنْتُمْ عَاكِفُونَ فِي الْمَسَاجِدِ تِلْكَ حُدُودُ اللَّهِ فَلَا تَقْرَبُوهَا كَذَالِكَ يُبَيِّنُ اللَّهُ آيَاتِهِ لِلنَّاسِ لَعَلَّهُمْ يَتُّقُونَ}