The burden of proof
الْبَيِّنَةُ عَلَى الْمُدَّعِي، وَالْيَمِينُ عَلَى مَنْ أَنْكَرَ
Al-bayyinatu 'ala-l-mudda'i, wa-l-yaminu 'ala man ankar.
"The burden of proof is on the claimant, and the oath is on the one who denies."
Narrated by Ibn Abbas. As-Sunan al-Kubra of al-Bayhaqi (hasan) · Nawawi's Forty · #33
A short reflection
The foundational principle of Islamic evidence. Absorbed into modern law the world over.