As newborn babes, desire the sincere milk of the word, that ye may grow thereby: As new-born babes - In the preceding chapter, 1 Peter 1:23, the apostle states that they had been born again; and as the new-born infant desires that aliment which nature has provided for it, so they, being born again - born from above, should as earnestly require that heavenly nourishment which is suited to their new nature; and this the apostle calls the sincere milk of the word, το λογικον αδολον γαλα, or, as some translate, the rational unadulterated milk; i.e. the pure doctrines of the Gospel, as delivered in the epistles and gospels, and as preached by the apostles and their successors. The rabbins frequently express learning to know the law, etc., by the term sucking, and their disciples are often denominated those that suck the breast. The figure is very expressive: as a child newly born shows an immediate desire for that nourishment, and that only, which is its most proper food; so they, being just born of God, should show that the incorruptible seed abides in them, and that they will receive nothing that is not suited to that new nature: and, indeed, they can have no spiritual growth but by the pure doctrines of the Gospel.
That ye may grow thereby - Εις σωτηριαν, Unto salvation, is added here by ABC, and about forty others; both the Syriac, the Arabic of Erpen, Coptic, Ethiopic, Armenian, Slavonic, Vulgate, and several of the ancient fathers. The reading is undoubtedly genuine, and is very important. It shows why they were regenerated, and why they were to desire the unadulterated doctrines of the Gospel; viz.: that they might grow up unto salvation. This was the end they should always have in view; and nothing could so effectually promote this end as continually receiving the pure truth of God, claiming the fulfillment of its promises, and acting under its dictates.