Hadithcore
Sunan Abi Dawud, 3417
sahih· Al-Albani

A similar tradition has also been transmitted by 'Ubadah b. al-Samit through a different chain of narrators, but the former tradition is more perfect. This version has:

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.

حَدَّثَنَا عَمْرُو بْنُ عُثْمَانَ، وَكَثِيرُ بْنُ عُبَيْدٍ، قَالاَ حَدَّثَنَا بَقِيَّةُ، حَدَّثَنِي بِشْرُ بْنُ عَبْدِ اللَّهِ بْنِ يَسَارٍ، قَالَ عَمْرٌو حَدَّثَنِي عُبَادَةُ بْنُ نُسَىٍّ، عَنْ جُنَادَةَ بْنِ أَبِي أُمَيَّةَ، عَنْ عُبَادَةَ بْنِ الصَّامِتِ، نَحْوَ هَذَا الْخَبَرِ - وَالأَوَّلُ أَتَمُّ - فَقُلْتُ مَا تَرَى فِيهَا يَا رَسُولَ اللَّهِ فَقَالَ ‏"‏ جَمْرَةٌ بَيْنَ كَتِفَيْكَ تَقَلَّدْتَهَا ‏"‏ ‏.‏ أَوْ ‏"‏ تَعَلَّقْتَهَا ‏"‏ ‏.‏

References2 variants
In-Book Reference
Book 24, Hadith 2
English Reference
Book 23, Hadith 3410