صحيح البخاري
Sahih Bukhari
كتاب الصوم
The Book of As-Saum (The Fasting).
بَابُ إِذَا نَوَى بِالنَّهَارِ صَوْمًا:
(21) Chapter. If the intention of observing Saum (fast) was made in the daytime.
Hadith 1924
حَدَّثَنَا أَبُو عَاصِمٍ ، عَنْ يَزِيدَ بْنِ أَبِي عُبَيْدٍ ، عَنْ سَلَمَةَ بْنِ الْأَكْوَعِ رَضِيَ اللَّهُ عَنْهُ ، " أَنَّ النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ بَعَثَ رَجُلًا يُنَادِي فِي النَّاسِ يَوْمَ عَاشُورَاءَ : إِنَّ مَنْ أَكَلَ فَلْيُتِمَّ ، أَوْ فَلْيَصُمْ ، وَمَنْ لَمْ يَأْكُلْ فَلَا يَأْكُلْ " .
Narrated Salama bin Al-Akwa`: Once the Prophet ordered a person on 'Ashura' (the tenth of Muharram) to announce, "Whoever has eaten, should not eat any more, but fast, and who has not eaten should not eat, but complete his fast (till the end of the day).
