Almah versus Betulah
In the original in Hebrew, “Almah,” which is used in Isaiah 7:14, means a young woman in child bearing age and mature for nuptials. “Betulah,” which is used in Amos 5:2, means a physical virgin, pure and immature as a lamb for sacrifice.
A lamb from the flock, to be chosen for a holocaust, it had to be physically perfect and without blemish. In the case of the Suffering Servant Israel, or Messiah ben Joseph, he would have to be spiritually without blemish, as one who had never done any wrong nor spoken any falsehood. (Isa. 53:9)
How could have Israel attained to that perfection, and then be sacrificed for the sins of Judah? Through the universal equalizer, which is death, as it cancels all. Before we were born, we had nothing to blemish our being perfect, because we did not exist. Whatever we did, enjoyed or suffered during our span of life on earth, as a result of the law of cause-and-effect, it’s all left behind as we experience death, the universal equalizer, as it leads us back into our previous condition of perfection, because we won’t exist.
Now, back to our theme, Isaiah in 7:14 is speaking of Israel as Almah, giving birth to a child, which according to I Kings 11:36, would remain forever as Immanuel, (Isa. 8:8) so that God would not have to break His “evelasting” covenant with Mankind through Noah. (Gen. 9:8-17)
Amos in 5:2 is speaking of Israel as Betulah, ready for the sacrificial redemption of Judah, spiritually perfect and without blemish for having had all his sins made as white as snow, according to Isaiah 1:18, and cancelled out by the imminent universal equalizer in death, predicted in Jacob’s prophecy of Shiloh. (Gen. 49:10)
Conclusion: Isaiah 7:14, therefore, depicts that phase of Israel as Almah giving birth to the child Judah. And Amos 5:2 depicts that phase of Israel as Betulah dying of her pangs in a sacrificial holocaust to God, so that Judah could survive and his descendants be seen in a long life, and the will of the Lord be accomplished through him. (Isa. 53:10)