Beginning, middle and ending of all beings

First mode of meditating on the LORD is as ATMA, the antaryami, the in dweller or SOUL.
The other mode as taking up an external entity as he is beginning, middle and end of all beings (living and non living).

Lord states:
अहमादिश्च मध्यं च भूतानामन्त एव च।।10.20।।

Again:
सर्गाणामादिरन्तश्च मध्यं चैवाहमर्जुन।
अध्यात्मविद्या विद्यानां वादः प्रवदतामहम्।।10.32।।

Bhutanam in 10.20 means the living beings; sarganaam in 10.32 means the creation(s) as a whole. This includes all living and non living beings.... He is the beginning, middle and end of living beings (microcosms) as well as the worlds (macrocosms) in different cycles of time....


There are other great symbols:
Among Adityas he is Vishnu
Among Rudras he is Sankara
Among Vasus he is Pavaka (fire)
Among the maintainers of law and order He is Yama
Among daemons he is Prahlada
Among counters he is Time. (He is Time of Time also)
Among wielders of weapons, he is Rama, son of Dasaratha.
Among senses (indriyas) he is Manas.

All these vibhutis are very useful to continuously remember the LORD. The very thought that among the "senses" he is the mind!

So, every "thought" is rooted in him, moves in him and finally rests in him alone. But due to the way it is put to grow, it may be taken by the evil tendencies for a temporary period. When the thoughts are controlled by the evil tendencies, due to ignorance (i.e., not acknowledging the true source, abode and final goal of thoughts as LORD) they lead to unwanted results that cause harm to the individual and the the environment. {remember that the evil tendencies due to ignorance are only temporary. They have no endurance to exist forever! }

The thought (of psychological plane) manifests as word and action in the emotional and physical planes.

Just by acknowledging the fact that not even a single action/thing, word or thought exists beyond the LORD himself gives eternal peace.

om tat sat.