Thus, though the circumstances of God’s covenant with Abraham (circumcision) is abolished, yet the substance (to be our God, and the God of our seed) remains. This might further be shown in many hundreds of instances, for the substance of all the Jewish sacrifices and sacraments, both ordinary and extraordinary, of their Sabbaths, their fasts, their feasts, and similar things, remain, though the circumstances, as shadows, have vanished away. Hence it is that many promises made to them are applied by the apostles to Christians, like, “I will not fail thee, nor forsake thee” (Heb. 13:5), and in general it is said, “The promise is to you and to your children, and to all that are afar off” (Acts 2:39).

Hereby we may learn what use to make of the Old Testament, even of those promises and privileges which in some particular respects were appropriated to the Jews, by observing the substance and distinguishing it from the circumstance. Thus shall we find that to be true which the apostle spoke of all the things which were written earlier, namely, that “they were written for our learning” (Rom. 15:4). In this respect the same apostle says of the things recorded of Abraham, “it was not written for his sake alone” (Rom. 4:23), and again of the things recorded of the Israelites, “they are written for our admonition” (1 Cor. 10:11). By this we may learn how to apply the preface to the Ten Commandments, which mentions the deliverance of Israel out of the bondage of Egypt.

Pray therefore for the spirit of illumination to discern between substance and circumstance, in reading the Old Testament especially.

William Gouge, Building a Godly Home: A Holy Vision for Family Life, 182-183.