Musar for Chullin 278:12

There is an enigmatic statement in the Talmud Chullin 139 which reads: משה מן התורה מנין? Whence do we have evidence in the Torah that Moses existed? The Talmud answers that this is proven from Genesis 6,3 where the Torah refers to G–d's spirit not being able to predominate in man while the latter is flesh, i.e. בשגם בשר. The numerical value of the word בשגם is 345, the same as the numerical value of the name משה. [The Talmud's query must be understood as "where is Moses' name alluded to already in the story leading up to the deluge?" Ed.]