Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
Qurʾān Bukhārī Muslim Nasāʾī Abū Dāwūd Tirmidhī Ibn Mājah Mālik Aḥmad Dārimī Ḥākim Ibn Ḥibbān Ṭabarānī Nasāʾī's Kubrá Bayhaqī al-Luʾluʾ wa-al-Marjān Ibn Rajab's Fifty Riyāḍ al-Ṣāliḥīn Aḥmad's Zuhd Suyūṭī
suyuti:3777a –

The Prophet said: "The best of charity is when a Muslim man gains knowledge, then he teaches it to his Muslim brother." (Using translation from Ibn Mājah 243)   

السيوطي:٣٧٧٧a –

"أفضل الصدقة : أن يتعلَّمَ المرءُ المسلمُ علما، ثم يُعَلِّمَه أخاهُ المسلم".  

[هـ] ابن ماجة عن أبي هريرة

See similar narrations below:

Collected by Ibn Mājah
ibnmajah:243 – Yaʿqūb b. Ḥumayd b. Kāsib al-Madanī > Isḥāq b. Ibrāhīm > Ṣafwān b. Sulaym > ʿUbaydullāh b. Ṭalḥah > al-Ḥasan al-Baṣrī > Abū Hurayrah

The Prophet said: "The best of charity is when a Muslim man gains knowledge, then he teaches it to his Muslim brother."  

ابن ماجة:٢٤٣ – حَدَّثَنَا يَعْقُوبُ بْنُ حُمَيْدِ بْنِ كَاسِبٍ الْمَدَنِيُّ حَدَّثَنِي إِسْحَاقُ بْنُ إِبْرَاهِيمَ عَنْ صَفْوَانَ بْنِ سُلَيْمٍ عَنْ عُبَيْدِ اللَّهِ بْنِ طَلْحَةَ عَنِ الْحَسَنِ الْبَصْرِيِّ عَنْ أَبِي هُرَيْرَةَ

أَنَّ النَّبِيَّ ﷺ قَالَ أَفْضَلُ الصَّدَقَةِ أَنْ يَتَعَلَّمَ الْمَرْءُ الْمُسْلِمُ عِلْمًا ثُمَّ يُعَلِّمَهُ أَخَاهُ الْمُسْلِمَ