Sahih Muslim 1111
Sahih Muslim · Book 13: The Book of Fasting · The strict prohibition of intercourse during the day in Ramadan for one who is fasting; And the obligation of offering major expiation and the definition thereof; And that it is obligatory for both the one who can afford it and the one who cannot afford it, and it remains an obligation for the one who cannot afford it until he has the means
حَدَّثَنَا عَبْدُ بْنُ حُمَيْدٍ ، أَخْبَرَنَا عَبْدُ الرَّزَّاقِ ، أَخْبَرَنَا مَعْمَرٌ ، عَنِ الزُّهْرِيِّ ، بِهَذَا الإِسْنَادِ نَحْوَ حَدِيثِ ابْنِ عُيَيْنَةَ .
This hadith has been narrated with the same chain of transmitters on the authority of Zuhri.