عَنِ ابْنِ عَبَّاسٍ رَضِيَ اللَّهُ عَنْهُ قَالَ: أَرْسَلَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ إِلَى أَهْلِ قَرْيَةٍ عَلَى رَأْسِ أَرْبَعَةِ فَرَاسِخَ، أَوْ قَالَ: فَرْسَخَيْنِ يَوْمَ عَاشُورَاءَ، فَأَمَرَ مَنْ أَكَلَ أَنْ لَا يَأْكُلْ بَقِيَّةَ يَوْمِهِ، وَمَنْ لَمْ يَأْكُلْ أَنْ يُتِمَّ صَوْمَهُ
Sayyiduna Abdullah bin Abbas (may Allah be pleased with him) says that the Messenger of Allah (peace and blessings be upon him) sent a message on the tenth of Muharram to the settlements within four or two farsakh, that whoever has eaten something should not eat for the rest of the day, and whoever has not yet eaten should complete his fast.