And I will sow her unto Me in the earth - She whom God sows, is the Church, of whom God speaks as her, because she is the Mother of the faithful. After the example of her Lord, and by virtue of His Death, every suffering is to increase her. “The blood of Christians was their harvest-seed” . “The Church was not diminished by persecutions, but increased and the field of the Lord was even clothed with the richer harvest, in that the seeds, which fell singly, arose multiplied” .
In the earth - “o He does not say “in their own land,” i. e., Judea, but “the earth.” The whole earth was to be the seed-plot of the Church, where God would sow her to Himself, plant, establish, cause her to increase, and multiply her mightily.” As he said, “Ask of Me, and I will give Thee the pagan for Thine inheritance, and the utmost parts of the earth for Thy possession” Psalms 2:8. Of this sowing, Jews were the instruments. Of them according to the flesh, Christ came; of them were the Apostles and Evangelists and all writers of Holy Scripture; of them was the Church first formed, into which the Gentiles were received, being, with them; knit into one in Christ.
I will ... have mercy upon her that had not obtained mercy - This which was true of Israel in its dispersion, was much more true of the Gentiles. These too, the descendants of righteous Noah, God had cast off for the time, that they should be no more His people, when he chose Israel out of them, to make known to them His Being, and His will, and His laws, and, (although in shadow and in mystery,) Christ who was to come. So God’s mercies again overflow His threatenings. He had threatened to Israel, that he should be “unpitied,” and no more His people; in reversing His sentence, He embraces in the arms of His mercy all who were not His people, and says of them all, that they should be “My people and beloved.” At one and the same time, was Israel to be thus multiplied, and “pity” was to be shown to those not pitied, and those who were “not God’s people,” were to become “His people.” At one and the same time were those promises fulfilled in Christ; the one through the other; Israel was not multiplied by itself; but through the bringing in of the Gentiles. Nor was Israel alone, or chiefly, brought into a new relation with God. The same words promised the same mercy to both, Jew and Gentile, that all should be “one in Christ,” all one Jezreel, one Spouse to Himself, one Israel of God, one Beloved; and that all, with one voice of jubilee. should cry unto Him, “my Lord and my God.”
And they shall say, Thou art my God, - (or rather, shall say, my God) There seems to be more affectionateness in the brief answer, which sums up the whole relation of the creature to the Creator in that one word, “Elohai, my God.” The prophet declares, as before, that, when God thus anew called them His people, they by His grace would obey His call, and surrender themselves wholly to Him. For to say, “my God,” is to own an exelusive relation to God alone. It is to say, my beginning and my end, my hope and my salvation, my whole and only good, in whom Alone I will hope, whom alone I will fear, love, worship, trust in, obey and serve, with all my heart, mind, soul and strength; my God and my all.