Chronology and Mysticism

Exodus says that Israel was in Egypt 430 years, Genesis says 400. Can we just round them off to make them coincide?

Tyconius ( The Book of Rules ) isn’t satisfied with that. Perhaps, he suggests, “they were not in slaver for the whole time? We need to find out, therefore, when the slavery began: and this is easy to learn.” He points out that slavery began after Joseph’s death, and says: “if the people’s slavery began after Joseph’s death, then we subtract 80 years of Joseph’s reign - he reigned from the age of 30 to the age of 110 - from the 430 years of their stay in Egypt; and there remain, for Israel’s slavery, 350 years - which God called 400.” The extra fifty years arise from the fact that here a whole (100) represents a part (50 actual years).

What’s intriguing about this is that Tyconius also writes a good bit about the symbolism of biblical numbers, discussing 7, 10, and 12 at length. Like other early writers, Tyconius sees no conflict at all between chronological and mystical interpretation.