أقسط
Aqsaṭa
To do justice; to act with fairness and equity.
What it means
Aqsaṭa means to act justly, to give each party its due share. Its participle muqsiṭ names the one who acts with equity. It is close in meaning to ʿadala and the noun ʿadl, and the Quran uses both groups of words for the same duty. The Quran says that God loves those who act justly (al-muqsiṭīn) in the passages dealing with settlement between two parties (49:9) and with dealings with those who have not fought against the believers (60:8). The command to be just is addressed to every Muslim in every dealing, whatever the feelings he holds toward the other party.
Often misunderstood as
That justice is a matter for judges alone, when the Quran asks every believer to act with equity.
What the sources say
The Quran also says that hatred of a people must not lead the believers to be unjust, and bids them be just because that is nearer to taqwa (5:8).
Term and Arabic as listed in Ismail al Faruqi, Toward Islamic English (International Institute of Islamic Thought, 1995), p. 44, listed as AQSAṬA. The definition is restated here.