Hadithcore
Mishkat al-Masabih, 249

Al-Hasan reported in <i>mursal</i> form that God’s messenger said, “If death comes to anyone when he is seeking knowledge with the purpose of using it to revivify Islam, there will be only one degree between him and the prophets in paradise.” Darimi transmitted it.

عَنِ الْحَسَنِ مُرْسَلًا قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «مَنْ جَاءَهُ الْمَوْتُ وَهُوَ يَطْلُبُ الْعِلْمَ لِيُحْيِيَ بِهِ الْإِسْلَامَ فَبَيْنَهُ وَبَيْنَ النَّبِيِّينَ دَرَجَةٌ وَاحِدَةٌ فِي الْجَنَّةِ» . رَوَاهُ الدَّارمِيّ

References1 variant
In-Book Reference
Book 2, Hadith 46