मया ततमिदं सर्वं जगदव्यक्तमूर्तिना।मत्स्थानि सर्वभूतानि न चाहं तेष्ववस्थितः॥
mayā tatam idaṃ sarvaṃ jagad avyakta-mūrtināmat-sthāni sarva-bhūtāni na cāhaṃ teṣvavasthitaḥ
Word by word
The verse says
All this world is spread out by me, in a form that does not appear. All beings rest in me, and I do not rest in them.
In plain words
Two halves, and the second one is deliberate.
Everything is in him. He is not in everything.
That sounds like a small distinction. The next verse shows it is not, by immediately saying the opposite.
Where you've felt this · in community
Every house on your street gets its water from the same reservoir, twenty miles outside town. The water is in every kitchen on the street — in the kettle, the bucket, the glass by the bed. The reservoir is in nobody's kitchen.
Going deeper
Being the source of something is not the same as being a part of it, and that is the whole content of the line.
If everything rests in him, he cannot be one of the things resting. A container is not among its contents. The moment you picture him as inside the world somewhere — a presence in a particular place, however grand — you have made him one more item on the list, and the list is precisely what he is said to be holding.
This is why the verse spends its second half taking something back. It is guarding against the one picture everybody naturally forms.
For a reader the practical effect is on where you look. Searching the world for God is searching the contents for the container, which is not a difficult task. It is a badly framed one.