The story of the youth of Moses is, as is commonly the case with great heroes, of secondary origin; moreover, the circumstances of his birth as related in Exod.
Kadesh (holy) was 1 Exod.
Collections of laws are found in Deuteronomy and in exilic and post-exilic writings; groups of a relatively earlier type are preserved in Exod.
The folk-etymology of the word Passover given in Exod.