It is a farḍ kifâyah. The imam must appoint enough qualified judges; those who are qualified must accept the positions if they are asked and there are no others to replace them. If there are others (who are qualified), then it is better for one to avoid it. 1714 Its prerequisites include being a free Muslim man1715 with intact hearing, vision, and speech, who is trustworthy and knowledgeable.
وَهُوَ فَرْضُ كِفَايَةٍ، يَلْزَمُ اْلإِمَامَ نَصْبُ مَنْ يُكْتَفِى بِهِ فِيْ اْلقَضَاءِ، وَيَجِبُ عَلىٰ مَنْ يَصْلُحُ لَهُ، إِذَا طُلِبَ وَلَمْ يُوْجَدْ غَيْرُهُ، اْلإِجَابَةُ إِلَيْهِ. وَإِنْ وُجِدَ غَيْرُهُ، فَاْلأَفْضَلُ تَرْكُهُ. وَمِنْ شَرْطِهِ أَنْ يَكُوْنَ رَجُلاً، حُرًّاً، مَسْلِمًا،