Says the Shaykh Abu Ja'far: Verily Allah, Who is Blessed and Exalted above all others, has commanded us to be just, while He Himself treats us with something even better, namely, grace (tafaddul2). And that is because He, the Glorious and Mighty says:
“Whoso bringeth a good deed will receive tenfold the like thereof; while whoso bringeth an evil deed will be awarded the like thereof; and they shall not be wronged” (Qur'an 6:160).
Justice (al-`adl) means that He requites3 a good act with a good act and an evil act with an evil act. The Prophet said: No man ever enters Paradise by virtue of his (good) actions (alone), except by the mercy of Allah the Glorious and Mighty.