عَنْ يَحْيَى بْنِ هِنْدٍ، عَنْ أَسْمَاءَ بْنِ حَارِثَةَ رَضِيَ اللَّهُ عَنْهُ أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ بَعَثَهُ، فَقَالَ: ((مُرْ قَوْمَكَ بِصِيَامِ هَذَا الْيَوْمِ))، قَالَ: أَرَأَيْتَ إِنْ وَجَدْتُّهُمْ قَدْ طَعِمُوا؟ قَالَ: ((فَلْيُتِمُّوا آخِرَ يَوْمِهِمْ))
Narrated by Sayyiduna Asma bin Haritha (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) instructed him, saying: Order your people to fast on this day. He said: If they have already eaten, then what is your opinion? The Prophet (peace and blessings be upon him) said: Even then, let them fast for the remainder of the day.