וְנָהָרּ֙ יֹצֵ֣א מֵעֵ֔דֶן לְהַשְׁק֖וֹת אֶת־הַגָּ֑ן וּמִשָּׁם֙ יִפָּרֵ֔ד וְהָיָ֖ה לְאַרְבָּעָ֥ה רָאשִֽׁים׃
And a river went out of Eden to water the garden; and from thence it was parted, and became four heads.
Read Jewish philosophical commentary on Genesis 2:10: and classical philosophical sources.