4. That the righteousness of the law--"the righteous demand," "the requirement" [ALFORD], Or "the precept" of the law; for it is not precisely the word so often used in this Epistle to denote "the righteousness which justifies" (Ro 1:17; 3:21; 4:5, 6; 5:17, 18, 21), but another form of the same word, intended to express the enactment of the law, meaning here, we believe, the practical obedience which the law calls for.
      might be fulfilled in us--or, as we say, "realized in us."
      who walk--the most ancient expression of the bent of one's life, whether in the direction of good or of evil (Ge 48:15; Ps 1:1; Isa 2:5; Mic 4:5; Eph 4:17; 1Jo 1:6, 7).
      not after--that is, according to the dictates of
      the flesh, but after the spirit--From Ro 8:9 it would seem that what is more immediately intended by "the spirit" here is our own mind as renewed and actuated by the Holy Ghost.

JFB.