The Egyptian Book of the dead by P. Le Page Renouf and Edouard Naville

4. _The drowning of his mother_ ⁂⁂⁂⁂⁂⁂⁂⁂⁂.

_Drowning_ maybe too strong a word, but immersion at least is meant. We are at present without any other reference to this incident in the career of the goddess Isis.