The Prophet ﷺ said, "I dreamt that I was cleaning my teeth with a Siwak and two persons came to me. One of them was older than the other and I gave the Siwak to the younger. I was told that I should give it to the older and so I did."  

أَنَّ النَّبِيَّ ﷺ قَالَ أَرَانِي أَتَسَوَّكُ بِسِوَاكٍ فَجَاءَنِي رَجُلاَنِ أَحَدُهُمَا أَكْبَرُ مِنَ الآخَرِ فَنَاوَلْتُ السِّوَاكَ الأَصْغَرَ مِنْهُمَا فَقِيلَ لِي كَبِّرْ فَدَفَعْتُهُ إِلَى الأَكْبَرِ مِنْهُمَا قَالَ أَبُو عَبْدِ اللَّهِ اخْتَصَرَهُ نُعَيْمٌ عَنِ ابْنِ الْمُبَارَكِ عَنْ أُسَامَةَ عَنْ نَافِعٍ عَنِ ابْنِ عُمَرَ