Hadith 31-282

وَبِإِسْنادِهِ عَنْ عَلِيِ‏ عَلَيْهِ السَّلامُ قالَ: ما شَبِعَ النَّبِيُ‏ صَلَّى اللهُ عَلَيْهِ وَآلِهِ مِن خُبزِ بُرٍّ ثَلاثَةَ أيَّامٍ حَتّى‏ مَضى‏ لِسَبيلِهِ.

According to the same documentation, on the authority of Ali (a.s.), “God’s Prophet (S) never ate a full meal of whole-wheat bread for three days in a row for as long as he lived.”