Gunas and Kosas

[Srikrishna Ghadiyaram]

Hari Om !!

I read in "Vedanta for Beginners" by Swami Sivananda that 'Sattva mixed
with Tamas' is the Guna found in Manomaya Kosa; and 'Sattva mixed with
Rajas' is the Guna found in Vijnanamaya Kosa.

How can the above statement be explained. We read that from the Sattva
aspect of each of  the five elements individual Jannendriyas formed, and
from the combined Sattva aspect of these five elements Antahkarana formed.
So, where are the Tamas and Rajas of Manomaya and Vijnanamaya coming from ?

Also in the same book I read 'Malina Sattva' (mixed with Rajas and Tamas )
is found in Anandamaya Kosa incontrast contrast wtih Suddha-Sattva of which
Maya is embodiment. If individual Avidya is coming from 'Maya' itself how
can it have mixed aspect differing from 'Maya' itself ?

Please direct me if there is any book I can read to understand this aspect
of Gunas better.

Om Namo Narayanaya !!

Srikrishna