8. He--Jehovah.
      hath showed thee--long ago, so that thou needest not ask the question as if thou hadst never heard (Mic 6:6; compare De 10:12; 30:11-14).
      what is good--"the good things to come" under Messiah, of which "the law had the shadow." The Mosaic sacrifices were but suggestive foreshadowings of His better sacrifice (Heb 9:23; 10:1). To have this "good" first "showed," or revealed by the Spirit, is the only basis for the superstructure of the moral requirements which follow. Thus the way was prepared for the Gospel. The banishment of the Jews from Palestine is designed to preclude the possibility of their looking to the Mosaic rites for redemption, and shuts them up to Messiah.
      justly . . . mercy--preferred by God to sacrifices. For the latter being positive ordinances, are only means designed with a view to the former, which being moral duties are the ends, and of everlasting obligation (1Sa 15:22; Ho 6:6; 12:6; Am 5:22, 24). Two duties towards man are specified--justice, or strict equity; and mercy, or a kindly abatement of what we might justly demand, and a hearty desire to do good to others.
      to walk humbly with thy God--passive and active obedience towards God. The three moral duties here are summed up by our Lord (Mt 23:23), "judgment, mercy, and faith" (in Lu 11:42, "the love of God"). Compare Jas 1:27. To walk with God implies constant prayer and watchfulness, familiar yet "humble" converse with God (Ge 5:24; 17:1).

JFB.