'First born' in the Bible

For a voice as of a woman in pangs, have I heard Anguish as of her that is bearing her firstborn. The voice of the daughter of Zion! She gaspeth for breath, She spreadeth forth her palms, - Surely woe to me! For my soul fainteth before murderers.

With weeping, shall they come in, And with supplications, will I lead them, I will bring them unto rivers of waters By a smooth way, wherein they shall not stumble, - For I have become, to Israel, a father, And as for Ephraim, my firstborn, is he!