ENOfficial
Al-Walid said : I asked Abu `Amr: What are they writing? He said: The sermon which he heard that day.
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا عَلِيُّ بْنُ سَهْلٍ الرَّمْلِيُّ، قَالَ حَدَّثَنَا الْوَلِيدُ، قَالَ قُلْتُ لأَبِي عَمْرٍو مَا يَكْتُبُوهُ قَالَ الْخُطْبَةَ الَّتِي سَمِعَهَا يَوْمَئِذٍ مِنْهُ .
sunnah.com