5 And in mercy shall the throne be established: and he shall sit upon it in truth in the tabernacle of David, judging, and seeking judgment, and hasting righteousness.
Christ will be the Judge and putting his people in place as under-judges (one man can't do it all!) in circumstances reminiscent of the government in the Book of Mormon and in the Old Testament book of Judges.
Then there is this phrase about "hasting righteousness". This is could cover the range of promulgating scripture and prophets that preach righteousness, all the way to eliminating unrighteousness (people). It is said there will be a burning of chaff, which is emblematic of this elimination of bad folk (a much larger group than many are ready to acknowledge).
Isaiah sees this process going faster into the future. It is interesting to think about how this vision is describing the present situation. It doesn't sound lackadaisical and letting wickedness act as it has done in the past, basically "I can get away with evil for a long time with impunity". It sounds like this won't happen so readily as it had previously. Righteousness is coming and it is coming quickly.
