The word adl means equity. It is used in the Koran in quasi-legal contexts, but elsewhere to mean being fair or fairness. The Koran employed the term adl but relatively rarely 14 times in the sense of justice or equity and in a much broader fashion, vide ta'dlin (6:70), adlun (2:48, 123, 282; 4:58, 85, 5:95, 106; 6:70, 16:76, 106:90, 49:9, 65:2) and li adli (42:15). While God's words are described as adl in 6:115.
Almost as important as adl is near synonym qist means giving fair measure. The root q-s-l appears in various forms and with various glosses, often linked to judging in judicial matter (2:282), sometimes as a mere synonym of adl (49:9), more generally as the virtue equity: "O you who believe! Be upright in equity (kunu qawwamina bi-l-qist) , witnesses to God" (4:135). God likewise will act with qist (21:47). The exact scope of qist is not spelled out in the Koran, rather, the term appeals to the sense of virtue latent in its listeners, inculcated by moral education and moral exemplars.
All Muslims believe that God is Just and that justice is one of the divine attributes of beauty (jamal). The basis of this belief is the Koranic negation of any possibility of injustice on the part of God, referring to Him as being Upright in Justice: "Verily, God wronged not even the weight of an atom" (4:40), "Verily, God wronged not mankind in anything