World Wide Study Bible
a Bible passage
13. useth—Greek, "partaketh," that is, taketh as his portion. Even strong men partake of milk, but do not make milk their chief, much less their sole, diet.
the word of righteousness—the Gospel wherein "the righteousness of God is revealed from faith to faith" (Ro 1:17), and which is called "the ministration of righteousness" (2Co 3:9). This includes the doctrine of justification and sanctification: the first principles, as well as the perfection, of the doctrine of Christ: the nature of the offices and person of Christ as the true Melchisedec, that is, "King of righteousness" (compare Mt 3:15).