(15) CHAPTER. The Statement of Allah: “It is made lawful for you to have sexual relations with your wives on the night of the As-Saum (the fasts). They are Libãs [i.e., body cover or screen or Sakan (i.e., ‘you enjoy the pleasure of living with her’ — as in the Verse 7:189) — Tafsir At-Tabari], for you, and you are the same for them. Allah knows that you used to deceive yourselves, so He turned to you (accepted your repentance) and forgave you. So, now have sexual relations with them and seek that which Allah has ordained for you (offspring)…” (V.2:187)
1915. Narrated Al-Bara: It was the custom among the companions of Muhammad, peace be upon him, that if any of them was observing As-Saum (fast) and the food was presented [for Iftar – breaking his Saum (fast)], but he slept before eating, he would not eat that night and the following day till sunset.
Qais bin Sirma Al-Ansari was observing Saum (fast) and came to his wife at the time of Iftar and asked her whether she had anything to eat. She replied, “No, but I would go and bring something for you.” He used to do hard work during the day, so he was overwhelmed by sleep and slept. When his wife came and saw him, she said, “Disappointment for you.” When it was midday on the following day, he fainted and the Prophet, peace be upon him, was informed about the whole matter; upon which the following Verses were revealed: “It is made lawful for you to have sexual relations with your wives on the night of As-Saum (the fasts)…”
So they were rejoiced greatly by it. And then Allah also revealed:
“…And eat and drink until the white thread (light) of dawn appears to you distinct from the black thread (darkness of night)…” (V.2:187)