Therefore he saith, Awake thou that sleepest, and arise from the dead, and Christ shall give thee light. This is evidently intended to give an additional impulse to the Ephesians to walk as children of the light; but a difficulty arises as to the source of the quotation.
There is no difficulty with the formula, "he saith," which, like the same expression in Ephesians 4:8, is clearly to be referred to God. But no such words occur in the Old Testament. The passage that comes nearest to them is Isaiah 60:1," Arise, shine; for thy light is come, and the glory of the Lord hath risen upon thee."
The simplest and best explanation is, not that the apostle quoted from any lost book, but flint he did not mean to give the words, but only the spirit of the passage. This is evident from his introducing the word "Christ."
It must be owned that the apostle makes a very free use of the prophet's words. But the fundamental idea in the prophecy is, that when the Church gets the light of heaven, she is not to lie still, as it' she were asleep or dead, but is to be active, is to make use of the light, is to use it for illuminating the world.
The apostle maintains that the Ephesian Church had got the light of heaven; she, therefore, was not to sleep or loiter, but spring forth as if from the grave, and pour light on the world. The changes which the apostle makes on the form of the prophecy are remarkable, and show that it was to its spirit and substance rather than to its precise form and letter that he attached the authority of inspiration.