Sayyiduna ‘Adi bin Hatim (may Allah be pleased with him) narrated that when this verse was revealed:“until the white thread becomes distinct to you from the black thread”(Al-Baqarah 187), I took a black thread and a white thread and placed them under my pillow, and I kept looking at them during the night, but their colors did not become clear to me. When morning came, I went to the Messenger of Allah (peace and blessings be upon him) and mentioned this to him. He said,“It means the darkness of the night (false dawn) and the whiteness of the day (true dawn).”

Sayyiduna Sahl bin Sa’d (may Allah be pleased with him) narrated that the verse was revealed:“Eat and drink until the white thread becomes distinct to you from the black thread”(Al-Baqarah 187), but the words“of the dawn”had not yet been revealed. Because of this, some people, when intending to fast, would take a black and a white thread and tie them to their feet, and they would not stop eating and drinking until both threads became clearly visible. Then Allah the Exalted revealed the words“of the dawn,”and then people realized that what was meant was the night and the day.

Sayyiduna Abdullah bin Umar (may Allah be pleased with them) narrated that the Messenger of Allah (peace and blessings of Allah be upon him) said: Bilal (may Allah be pleased with him) gives the call to prayer during the night, so you may continue eating and drinking until Ibn Umm Maktum gives the call to prayer.

Narrated by Sayyidah Aisha (may Allah be pleased with her): Bilal (may Allah be pleased with him) used to call the adhan during the latter part of the night, so the Messenger of Allah (peace and blessings be upon him) said: "Keep eating and drinking until Ibn Umm Maktum (may Allah be pleased with him) calls the adhan, for he does not call the adhan until the true dawn appears."

Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) narrates that the Noble Prophet (peace and blessings be upon him) said: Let not Bilal’s call to prayer prevent you from eating the pre-dawn meal (suhoor), for he gives the call to prayer during the night, or (he said) he calls so that those who are awake for worship may return to rest, and those who are still asleep may become alert. No one should think that dawn or true dawn (subh sadiq) has occurred. And the Prophet (peace and blessings be upon him) demonstrated the state of the rising of dawn with his fingers: he raised his fingers upward and then slowly brought them down, and then said: This is how (the dawn) appears.