I taught some persons of the people of Suffah writing and the Qur'an. A man of them presented to me a bow. I said: It cannot be reckoned property; may I shoot with it in Allah's path? I must come to the Apostle of of Allah ﷺ and ask him (about it). So I came to him and said : Messenger of Allah ﷺ, one of those whom I have been teaching writing and the Qur'an has presented me a bow, and as it cannot be reckoned property, may I shoot with it in Allah's path? He said: If you want to have a necklace of fire on you, accept it.  

عَلَّمْتُ نَاسًا مِنْ أَهْلِ الصُّفَّةِ الْكِتَابَ وَالْقُرْآنَ فَأَهْدَى إِلَىَّ رَجُلٌ مِنْهُمْ قَوْسًا فَقُلْتُ لَيْسَتْ بِمَالٍ وَأَرْمِي عَنْهَا فِي سَبِيلِ اللَّهِ ﷻ لآتِيَنَّ رَسُولَ اللَّهِ ﷺ فَلأَسْأَلَنَّهُ فَأَتَيْتُهُ فَقُلْتُ يَا رَسُولَ اللَّهِ رَجُلٌ أَهْدَى إِلَىَّ قَوْسًا مِمَّنْ كُنْتُ أُعَلِّمُهُ الْكِتَابَ وَالْقُرْآنَ وَلَيْسَتْ بِمَالٍ وَأَرْمِي عَنْهَا فِي سَبِيلِ اللَّهِ قَالَ إِنْ كُنْتَ تُحِبُّ أَنْ تُطَوَّقَ طَوْقًا مِنْ نَارٍ فَاقْبَلْهَا  

I said: What do you think about it, Messenger of Allah? He said: A live coal between your shoulders which you have put around your neck or hanged it.  

عَنْ عُبَادَةَ بْنِ الصَّامِتِ نَحْوَ هَذَا الْخَبَرِ وَالأَوَّلُ أَتَمُّ فَقُلْتُ مَا تَرَى فِيهَا يَا رَسُولَ اللَّهِ فَقَالَ جَمْرَةٌ بَيْنَ كَتِفَيْكَ تَقَلَّدْتَهَا أَوْ تَعَلَّقْتَهَا