Sunan Ibn Majah, Book 31, Hadith 3613 (In-Book) ⓘ
It was narrated from Abu Kabshah Al-Anmari that the Prophet used to be cupped on his head and between his shoulders, and he said: “Whoever lets blood from these places, it does not matter if he does not seek treatment for anything else.”
حَدَّثَنَا مُحَمَّدُ بْنُ الْمُصَفَّى الْحِمْصِيُّ، حَدَّثَنَا الْوَلِيدُ بْنُ مُسْلِمٍ، حَدَّثَنَا ابْنُ ثَوْبَانَ، عَنْ أَبِيهِ، عَنْ أَبِي كَبْشَةَ الأَنْمَارِيِّ، أَنَّهُ حَدَّثَهُ أَنَّ النَّبِيَّ ـ صلى الله عليه وسلم ـ كَانَ يَحْتَجِمُ عَلَى هَامَتِهِ وَبَيْنَ كَتِفَيْهِ وَيَقُولُ " مَنْ أَهْرَاقَ مِنْهُ هَذِهِ الدِّمَاءَ فَلاَ يَضُرُّهُ أَنْ لاَ يَتَدَاوَى بِشَىْءٍ لِشَىْءٍ " .
also referenced under: Hadith 3484 (Reference) & Volume 4, Book 31, Hadith 3484 (DarusSalam)