Sahih al-Bukhari, Hadith 5410 ⓘ
Narrated Abu Hazim: that he asked Sahl, "Did you use white flour during the lifetime of the Prophet ?" Sahl replied, "No. Hazim asked, "Did you use to sift barley flour?" He said, "No, but we used to blow off the husk (of the barley).
حَدَّثَنَا سَعِيدُ بْنُ أَبِي مَرْيَمَ، حَدَّثَنَا أَبُو غَسَّانَ، قَالَ حَدَّثَنِي أَبُو حَازِمٍ، أَنَّهُ سَأَلَ سَهْلاً هَلْ رَأَيْتُمْ فِي زَمَانِ النَّبِيِّ صلى الله عليه وسلم النَّقِيَّ قَالَ لاَ. فَقُلْتُ فَهَلْ كُنْتُمْ تَنْخُلُونَ الشَّعِيرَ قَالَ لاَ وَلَكِنْ كُنَّا نَنْفُخُهُ.
also referenced under: Book 70, Hadith 38 (In-Book) & Volume 7, Book 65, Hadith 321 (USC-MSA)