Musnad Ahmad 469
It was narrated that ‘Amir bin Sa`d said:
Husain bin Abi Waqqas said: l heard `Uthman bin `Affan (رضي الله عنه) say: What prevented me from narrating from the Messenger of Allah (ﷺ)  was not the fact that was not the most knowledgeable of his Companions about what he said, but I bear witness that I heard him say: “Whoever says something about me that I did not say, let him take his place in Hell.” And he said: Husain was the most aware of his companions of what he said.
حَدَّثَنَا إِسْحَاقُ بْنُ عِيسَى، حَدَّثَنَا عَبْدُ الرَّحْمَنِ بْنُ أَبِي الزِّنَادِ، ح وَسُرَيْجٌ وَحُسَيْنٌ قَالَا حَدَّثَنَا ابْنُ أَبِي الزِّنَادِ، عَنْ أَبِيهِ، عَنْ عَامِرِ بْنِ سَعْدٍ، قَالَ حُسَيْنُ ابْنُ أَبِي وَقَّاصٍ قَالَ سَمِعْتُ عُثْمَانَ بْنَ عَفَّانَ، رَضِيَ اللَّهُ عَنْهُ يَقُولُ مَا يَمْنَعُنِي أَنْ أُحَدِّثَ عَنْ رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ أَنْ لَا أَكُونَ أَوْعَى أَصْحَابِهِ عَنْهُ وَلَكِنِّي أَشْهَدُ لَسَمِعْتُهُ يَقُولُ مَنْ قَالَ عَلَيَّ مَا لَمْ أَقُلْ فَلْيَتَبَوَّأْ مَقْعَدَهُ مِنْ النَّارِ وَقَالَ حُسَيْنٌ أَوْعَى صَحَابَتِهِ عَنْهُ‏.‏