(2) Knowledge
كتاب العلم
(1a) Chapter - Section 1
(1a) باب - الفصل الأول
Mishkat al-Masabih 203 
Abu Huraira reported God’s messenger as saying, “When a man dies no further reward is recorded for his actions, with three exceptions:
sadaqa which continues to be supplied, or knowledge from which benefit continues to be reaped, or the prayers of a good son for his dead father.” Muslim transmitted it.
وَعَنْ أَبِي هُرَيْرَةَ رَضِيَ اللَّهُ عَنْهُ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: " إِذَا مَاتَ الْإِنْسَانُ انْقَطَعَ عَمَلُهُ إِلَّا مِنْ ثَلَاثَةِ أَشْيَاءَ: صَدَقَةٍ جَارِيَةٍ أوعلم ينْتَفع بِهِ أوولد صَالح يَدْعُو لَهُ) رَوَاهُ مُسلم
 صَحِيحٌ  (الألباني)حكم :
Reference : Mishkat al-Masabih 203
In-book reference : Book 2, Hadith 6