The no-harm maxim

قاعدة لا ضرر ولا ضرار

The maxim 'no harm and no reciprocating harm' is among the great foundations of jurisprudence, taken from Abu Sa'id al-Khudri's hadith — the thirty-second of the Forty — which al-Darawardi's route in al-Daraqutni, al-Hakim and al-Bayhaqi extends as 'whoever harms, God harms him, and whoever makes things difficult, God makes things difficult for him'; Malik transmitted it mursal in the Muwatta' with no divergence reported by Ibn Abd al-Barr, who found no sound full chain for it, Khalid ibn Sa'd al-Andalusi declaring it never established with one, while al-Hakim graded its reported chain sahih on Muslim's condition and al-Nawawi notes it has routes that strengthen one another; its meaning negates harm both initiatory and retaliatory — one may not harm oneself or another, nor answer harm with harm save through lawful retribution — and the maxim serves to lift hardship from legal impositions and to ward off corruption (Jami' al-Ulum wal-Hikam pp. 667–668).