Amir b Sa'd b. Abi Waqqas reported (on the authority of his father that Allah's Messenger (ﷺ) addressing 'Ali said:

You are in the same position with relation to me as Aaron (Harun) was in relation to Moses but with (this explicit difference) that there is no prophet after me. Sa'd said: I had an earnest desire to hear it directly from Sa'd, so I met him and narrated to him what (his son) Amir had narrated to me, whereupon he said: Yes, I did hear it. I said: Did you hear it yourself? Thereupon he placed his fingers upon his ears and said: Yes, and if not, let both my ears become deaf.

حَدَّثَنَا يَحْيَى بْنُ يَحْيَى التَّمِيمِيُّ، وَأَبُو جَعْفَرٍ مُحَمَّدُ بْنُ الصَّبَّاحِ وَعُبَيْدُ اللَّهِ الْقَوَارِيرِيُّ وَسُرَيْجُ بْنُ يُونُسَ كُلُّهُمْ عَنْ يُوسُفَ الْمَاجِشُونِ، - وَاللَّفْظُ لاِبْنِ الصَّبَّاحِ - حَدَّثَنَا يُوسُفُ، أَبُو سَلَمَةَ الْمَاجِشُونُ حَدَّثَنَا مُحَمَّدُ بْنُ الْمُنْكَدِرِ، عَنْ سَعِيدِ بْنِ الْمُسَيَّبِ، عَنْ عَامِرِ بْنِ سَعْدِ، بْنِ أَبِي وَقَّاصٍ عَنْ أَبِيهِ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم لِعَلِيٍّ ‏

‏ أَنْتَ مِنِّي بِمَنْزِلَةِ هَارُونَ مِنْ مُوسَى إِلاَّ أَنَّهُ لاَ نَبِيَّ بَعْدِي ‏

‏ ‏.‏ قَالَ سَعِيدٌ فَأَحْبَبْتُ أَنْ أُشَافِهَ بِهَا سَعْدًا فَلَقِيتُ سَعْدًا فَحَدَّثْتُهُ بِمَا حَدَّثَنِي عَامِرٌ فَقَالَ أَنَا سَمِعْتُهُ ‏.‏ فَقُلْتُ آنْتَ سَمِعْتَهُ فَوَضَعَ إِصْبَعَيْهِ عَلَى أُذُنَيْهِ فَقَالَ نَعَمْ وَإِلاَّ فَاسْتَكَّتَا ‏.‏