Why is exile compared to pregnancy, and Redemption to birth?

Exile is likened to pregnancy, and the Redemption is likened to birth; as it is written, "For Zion has been in labor, and has given birth to her children."

Our Sages teach that when an infant is in his mother's womb, "his head is between his knees," not carrying out its function. It does not think, and though he has eyes they do not see. Also, "his mouth is closed and his navel is open"; i.e., his nourishment (for he eats what his mother eats) passes through his navel into his stomach and makes his body grow, rather than passing through his mouth, from which it would animate the heart and brain.

These two situations also characterize the Jewish people during the period of exile:

Since the Holy One, blessed be He, removed the revelation of His Presence from This World, the Children of Israel do not behold the Divine light. Moreover, the life-giving flow that wells from one's performance of mitzvos and good deeds does not enter through the mouth, from which it would animate the heart and brain, giving rise to a knowledge and love of G-d; rather, divine service is carried out frigidly, "a commandment which men perform by rote."

This is the essence of the spiritual meaning of exile.

Accordingly, the ultimate perfection of the days of Mashiach is a kind of birth -- a revelation of the light of G-d within the deepest recesses of a man's heart. As it is written, "The glory of G-d will be revealed, and all flesh [together] will see [that the mouth of G-d has spoken]"; and likewise too it is written, "For they shall see eye to eye [when G-d returns to Zion]."