CS, If Jews would have stayed the full 400 years, there would have been no other galus. The Chasam Sofer explains that Pesach was the cause for Tisha Beov that is why we eat eggs at the seder which falls on the same day as א’ת the first day of Pesach falls as Tisha Beov. It is like being hit by pebbles or a rock, many smaller galuses or a big one.
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