Ignorant of this mystery - The word “mystery” means properly what is “concealed, hidden, or unknown.” And it especially refers, in the New Testament, to the truths or doctrines which God had reserved to himself, or had not before communicated. It does not mean, as with us often, that there was anything unintelligible or inscrutible in the nature of the doctrine itself, for it was commonly perfectly plain when it was made known. Thus, the doctrine, that the division between the Jews and the Gentiles was to be broken down, is called a mystery, because it had been, to the times of the apostles, concealed, and was then revealed fully for the first time; Romans 16:25; Colossians 1:26-27; compare 1 Corinthians 15:51; Mark 4:11; Ephesians 1:9; Ephesians 3:3. Thus, the doctrine which the apostle was stating was one that until then had been concealed, or had not been made known. It does not mean that there was anything unintelligible or incomprehensive in it, but until then it had not been made known.
Lest ye should be wise in your own conceits - Paul communicated the truth in regard to this, lest they should attempt to inquire into it; should speculate about the reason why God had rejected the Jews; and should he elated with the belief that they had, by their own skill and genius, ascertained the cause. Rather than leave them to vain speculations and self-gratulation, he chose to cut short all inquiry, by stating the truth about; their present and future state.
Blindness - Or hardness; see Romans 11:7.
In part - Not totally, or entirely. They are not absolutely or completely blinded. This is a qualifying expression; but it does not denote what part or portion, or for what time it is to continue. It means that the blindness in respect to the whole nation was only partial. Some were then enlightened, and had become Christians; and many more would he.
To Israel - To the Jews.
Until the fulness of the Gentiles ... - The word “fulness” in relation to the Jews is used in Romans 11:12. It means until the abundance or the great multitude of the Gentiles shall be converted. The word is not used elsewhere in respect to the Gentiles; and it is difficult to fix its meaning definitely. It doubtless refers to the future spread of the Gospel among the nations; to the time when it may be said that the great mass, the abundance of the nations, shall be converted to God. At present, they are, as they were in the times of the apostle, idolators, so that the mass of mankind are far from God. But the Scriptures have spoken of a time when the gospel shall spread and prevail among the nations of the earth; and to this the apostle refers. He does not say, however, that the Jews may not be converted until all the Gentiles become Christians; for he expressly supposes Romans 11:12-15 that the conversion of the Jews will have an important influence in extending the gospel among the Gentiles. Probably the meaning is, that this blindness is to continue until great numbers of the Gentiles shall be converted; until the gospel shall be extensively spread; and then the conversion of the Jews will be a part of the rapid spread of the gospel, and will be among the most efficient and important aids in completing the work. If this is the case, then Christians may labor still for their conversion. They may seek that in connection with the effort to convert the pagan; and they may toil with the expectation that the conversion of the Jews and Gentiles will not be separate, independent, and distinct events; but will be inter-mingled, and will be perhaps simultaneous. The word “fulness” may denote such a general turning to God, without affirming that each individual shall be thus converted to the Christian faith.