{Speak not one against another} (m(8820)katalaleite all(886c)(936e)).
Prohibition against such a habit or a command to quit doing it,
with m(885c) and the present imperative of katalale(935c), old compound
usually with the accusative in ancient Greek, in N.T. only with
the genitive (here,  1Pe 2:12  3:16 ). Often harsh words about
the absent. James returns to the subject of the tongue as he does
again in  5:12  (twice before,  1:26  3:1-12 ). {Judgeth}
(krin(936e)). In the sense of harsh judgment as in  Mt 7:1  Lu
6:37  (explained by katadikaz(935c)). {Not a doer of the law, but a
judge} (ouk poi(8874)(8873) nomou, alla krit(8873)). This tone of
superiority to law is here sharply condemned. James has in mind
God's law, of course, but the point is the same for all laws
under which we live. We cannot select the laws which we will obey
unless some contravene God's law, and so our own conscience ( Ac
4:20 ). Then we are willing to give our lives for our rebellion
if need be.