God's taking the Jewish people out of Egypt with a mighty hand and an outstretched arm made it clear that they had been chosen as the God's nation. When Israel suffers, God's name is desecrated. This fact guarantees the eternal existence of Israel.
The Khazar king was puzzled. In what sense could the story of the Exodus, the Revelation at Sinai, or the account of the forefathers serve as a solid foundation for faith?