حَدَّثَنَا ابْنُ مَهْدِيٍّ عَنْ سُفْيَانَ عَنْ أَبِي إِسْحَاقَ عَنْ التَّمِيمِيِّ عَنِ ابْنِ عَبَّاسٍ فَذَكَرَ شَيْئًا قَالَ وَكَانَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يُكْثِرُ السِّوَاكَ قَالَ حَتَّى ظَنَنَّا أَوْ رَأَيْنَا أَنَّهُ سَيُنْزَلُ عَلَيْهِ
مسند امام احمد بن حنبل · Hadith 2573
It was narrated from Ibn 'Abbas (RA) and he mentioned something. He said: The Messenger of Allah (PBUH) used to use the siwak a great deal, to such an extent that we thought that Revelation would come down concerning it.
Translated by Dr. Muhammad Muhsin Khan · Reviewed by Islamic University of Madinah · Published March 2020