Isaiah 66:8
Who hath heard such a thing? who hath seen such things? Shall the earth be made to bring forth in one day? or shall a nation be born at once? for as soon as Zion travailed, she brought forth her children. Who hath heard such a thing? who hath seen such things? Shall the earth be made to bring forth in one day? or shall a nation be born at once? for as soon as Zion travailed, she brought forth her children.
The picture of a nation born in one day refers to the bodily resurrection from the grave, not to the inward new birth Jesus described to Nicodemus. Jesus in that conversation was speaking of the Spirit's work of cleansing the unregenerate heart before it is fit for the kingdom of Heaven and of God. As held on the other side, the same picture does not refer here to the resurrection of the body but illustrates the inward work of grace by which the Spirit cleanses the naturally defiled heart and brings about the new birth.
The verse shows that a nation can be born in a day, fulfilled when those appointed by God are converted to the truth. Many converted Jews will have an important part in future preparation to receive Christ and will help prepare the way for Him. Their growth follows the stages of a crop from blade to full grain, while the day of the Lord comes suddenly and unexpectedly.
Zion's travailing to bring forth her children means the church crying out in travail to bring forth souls born again. This travail is earnest wrestling with God in eager, earnest, importunate prayer for the impartation of the Holy Spirit bringing vitalizing power. In answer to fervent prayer God turns human hearts as He turns the waters of the sea. Zion must travail for perishing souls before she can see sinners born again. The Holy Spirit's converting work in the new birth comes only after the church arouses, becomes united with Christ and one another with self hidden, and labors with one spirit and one mind to minister present truth, with no such work seen until Zion thus travails in earnest labor.