{Cannot hate} (ou dunatai misein). Because of "the law of
moral correspondence" (Westcott), often in John for "inherent
impossibility" (Vincent). The brothers of Jesus here belong to
the unbelieving world (kosmos) which is unable to love Jesus
( 15:18,23,24 ) and which Jesus had already exposed ("testify,"
martur(935c),  5:42,45 ). This unbelieving "world" resented the
exposure ( 3:19 , cf.  18:37 ).