Ibn al-Salah wrote the classic introduction to hadith sciences (Muqaddima), organizing how narrators are graded, how chains work, and how hadith relates to fiqh. Imam al-Nawawi summarized it in al-Taqrib.
His work is a pillar of how isnad and diraya are taught in traditional curricula.
SeekersGuidance courses on hadith
SeekersGuidance
Structured study of Islamic sciences.