"Use this black seed. For indeed it contains a cure for every disease except As-Sam" And As-Sam is death. (Using translation from Tirmidhī 2041)  

قَالَ رَسُولُ اللهِ ﷺ «عَلَيْكُمْ بِهَذِهِ الْحِبَّةِ السَّوْدَاءِ فَإِنَّ فِيهَا شِفَاءً مِنْ كُلِّ دَاءٍ إِلَّا السَّامَ وَالسَّامُ الْمَوْتُ»  

“I heard Salim bin ‘Abdullah narrating from his father that the Messenger of Allah ﷺ said: ‘You should eat this black seed, for in it there is healing from every disease, except the Sam (death).’” (Using translation from Ibn Mājah 3448)   

عَنْ رَسُولِ اللهِ ﷺ قَالَ «عَلَيْكُمْ بِالْحَبَّةِ السَّوْدَاءِ فَإِنَّ فِيهَا شِفَاءً مِنْ كُلِّ دَاءٍ إِلَّا السَّامَ وَالسَّامُ الْمَوْتُ»