Let us analyze the name of Pharaoh. The decree of bondage in Mitzrayim was for 400 at the Bris Bein Habasarim. The chesbon of this number is because the geographic inheritance of Am Yisrael is composed of ten nations. The seven of Eretz Yisrael as we know it and another three named קיני קניזי קדמוני. The Medrash says at the beginning of Shmos that their future lands of Eretz Plus must be acquired with suffering. Hashem's chesbon of 400 years was reckoned with 40 years of galus for each land. The last three geographic areas are to be acquired by Am Yisrael in the Acharis Hayamim, but the seven of Eretz Yisrael would be accessible for us after 280 years of galus and servitude. However, we were enslaved to Mitzrayim only 210 years. We owed a debt of 70 years slavery to Mitzrayim, so how did we leave prematurely? The answer is that the first galus when the Beis Hamikdash was destroyed was for 70 years until we returned back to Eretz Yisrael. During those seventy years of galus, we made up for the missing 70 years from the 280.
תיב המל שני בפרט זכה לקידשה לעתיד לבוא
With this, Rav Kamai explains the difficulty in the Rambam, who writes that the first Beis Hamikdash, when it was destroyed, lost its original kedusha, which is in contrast to after the Second Beis Hamikdash's destruction, the kedusha nevertheless remained קדשה לשעתה וקדשה לעתיד לבוא. Why the difference? It should have been just the opposite because The Second Bayis was lacking five maalos that the First Mikdash possessed.
The answer is that as long as Yisrael owed a debt of 70 years of galus which was needed to inherit Eretz Yisrael, the kedusha was unable to remain. After the galus of Bavel, which lasted for seventy years, the debt was paid off, so when the Second Mikdash was built, its kedusha remained intact.
ומש תויתואו ומולח םושמ לארשי תוריח בריס הערפ
