He opened it to confirm his presumption regarding Sarah's hair.
In case of doubt the presumption was in favour of the state.
Moreover, among the Jewish families settled in the 5th century B.C. in Egypt (Elephantine) and Babylonia (Nippur), the Babylonian-Assyrian principles are in vogue, and the presumption that they were not unfamiliar in Palestine is strengthened further by the otherwise unaccountable appearance of Babylonian-Assyrian elements later in the Talmudic law.
It is not known at what school he was educated, nor at what college, though the presumption is in favour of Magdalen, Oxford, whence he drew so many members of his subsequent foundation, Corpus Christi.