Romans 11:25

For I would not, brethren
The apostle in order to raise the attention of the Gentiles to what he was about to deliver to them, not only styles them "brethren", expressing his affection for them, and their relation to him and other believing Jews, and to one another, being all one in Christ Jesus, partakers of the same grace, and heirs of the same glory; but also tells them, that what he had to acquaint them with was a "mystery", a thing secret and hidden, which had not been heard of and known, at least not so fully and clearly as he was about to reveal it; and because of his great respect for them, he was unwilling, as he says,

that ye should be ignorant of this mystery;
he was desirous that they should abound and improve in all spiritual knowledge and judgment, and, among the rest, be better informed of this particular article, the call of the Jews: and his view in apprizing them of it is expressed in the following clause,

lest ye should be wise in your own conceits:
lest they should imagine that they were the only wise and knowing persons, and be elated in their minds with their knowledge and understanding, and look with contempt upon the poor, blind, ignorant Jews, as if they were always to remain in such a state of darkness and infidelity. The thing he had to inform them of is,

that blindness in part is happened to Israel, until the fulness of the
Gentiles be come in;
by Israel is meant the Jews, the descendants of Jacob, whose name was Israel. Philo the Jew observes ^F2, that this name signifies (orasin yeou) , "the vision of God"; indeed, Jacob had it given him when he wrestled with the angel, and saw God face to face, though it does not seem to be for that reason; however, blindness had now befallen the Jews, who had been favoured with a divine revelation, with the knowledge of God, his will and worship; and none were more blind than those who were called the servants and messengers of the Lord of hosts, as the Scribes and Pharisees, the priests and princes of the Jewish world. This "blindness" designs their unbelief, the hardness of their hearts, and darkness of their understandings with respect to God himself, whom they knew not in Christ; not as the Father of Christ; nor even the perfections of his nature, particularly his righteousness; which was the reason of their setting up their own righteousness, and of their non-submission to the righteousness of Christ: they were blind as to the Messiah; they knew him not, when he came; they saw no beauty and comeliness in him; could not discern the characters of him in Jesus, though they were so manifest; and rejected him notwithstanding the clear evidence of his ministry and miracles. They were in the dark about the sense of the prophecies of the Old Testament; a vail was upon their hearts when they read them, so that they understood them not, and could not see their accomplishment in Christ; they were even ignorant of the law, the spiritual nature, true use, and right end and scope of it; and it is no wonder that the Gospel should be hidden from them. This blindness "happened" to them not by chance, but befell them by the decree, and according to the will of God, who hardens whom he pleases; and according to various predictions in the Old Testament, cited in ( Matthew 13:14 Matthew 13:15 ) ( John 12:39 John 12:40 ) ( Romans 11:8-10 ) ; and in righteous judgment, for since they liked not to retain God and his Christ in their knowledge, it was but just in God to give them up to reprobate minds, to judicial blindness, and hardness of heart: but then this blindness only happened to them "in part"; not that it was only in some measure or some degree, for it was total, they were darkness itself, and had no spiritual and evangelic light at all on whom it fell; but that this blindness was not general with respect to persons, there were some few, a seed, a remnant, that were delivered from it, though the far greater part of the nation were involved in it, and continue in it to this day; and will do, "until the fulness of the Gentiles be come in": that is, till the whole number of God's elect among them, be called and brought into the Gospel church state, which in the latter day will be very great; when the earth shall be filled with the knowledge of the Lord, as the waters cover the sea; when the kingdoms of this world shall become the kingdoms of our Lord and his Christ; and the abundance of the sea shall be converted, and the forces of the Gentiles shall come to the church, and multitudes of them shall flock thither, as doves to their windows: and since the blindness of the Jews is not yet removed, it seems plain that the full number of God's chosen ones among the Gentiles is not yet completed in regeneration; for as soon as ever they are all called and brought in, the vail will be taken away from the Jews, and they will be turned unto the Lord.