And not for that nation only, but that also he should gather together in one the children of God that were scattered abroad. And not for that nation only, etc. - These, and the preceding words in John 11:51, are John's explication of what was prophetic in the words of Caiaphas: as if John had said, He is indeed to die for the sins of the Jewish nation, but not for theirs alone, but for the sins of the whole world: see his own words afterwards, 1 John 2:1, 1 John 2:2.
Gather together in one - That he should collect into one body; - form one Church out of the Jewish and Gentile believers.
Children of God that were scattered abroad - Probably John only meant the Jews who were dispersed among all nations since the conquest of Judea by the Romans; and these are called the dispersed, John 7:35, and James 1:1; and it is because he refers to these only, that he terms them here, the children of God, which was an ancient character of the Jewish people: see Deuteronomy 32:5; Isaiah 43:6; Isaiah 45:11; Jeremiah 32:1. Taking his words in this sense, then his meaning is this: that Christ was to die, not only for the then inhabitants of Judea, but for all the Jewish race wheresoever scattered; and that the consequence would be, that they should be all collected from their various dispersions, and made one body. This comports with the predictions of St. Paul: Romans 11:1-32. This probably is the sense of the passage; and though, according to this interpretation, the apostle may seem to confine the benefits of Christ's death to the Jewish people only, yet we find from the passage already quoted from his first epistle, that his views of this subject were afterwards very much extended; and that he saw that Jesus Christ was not only a propitiation for their sins (the Jews) but for the sins of the whole world: see his 1st epistle, 1 John 2:2. All the truths of the Gospel were not revealed at once, even to the apostles themselves.