mano'haṅkṛtyupādānaṃ liṅgamekaṃ jaḍātmakam । avasthātrayamanveti jāyate mriyate tathā II 12 II
Constituted of mind and ego, the one insentient subtle body, goes through the three states; it is born and it dies.
The mind constitutes of I-ness and thought, is a part of subtle body together with organs of perception, organs of action and prāna. These bundle is called subtle body which is inert in nature - liṅgamekaṃ jaḍātmakam. This subtle body is called lingam here, because it is as the indicator (even though inert in nature), but it is the place where we are able to know our true nature. Only through the mind, Cit - Consciousness can be manifest in this experiential-world, therefore it is called as lingam.
This subtle body alone goes through the three states of experience and also goes through the death and birth. Life is all about the mind which is going through one state of experience to another state. Everyday the mind goes through waking, dreaming and deep sleep state, and after certain period of time, the same mind leaves the physical body at the time of death, and manifest again through another birth of the body.
Here is the conclusion of the mind's analysis.
Now we know that I - the absolute seer which is sentient in nature, lent the sentiency to the inert subtle body to experience the world. Because of the identification between I-ness and others factors, then the experiential of the world is possible. From here we can conclude that I-ness is the cause of samsāra. Because of I-ness, the objective become a projection of the individual. And I-ness is there because of the delusion/ignorance. But where is the delusion come from? To answer this question, we need to talk about the creation.
Next, ācārya wants to establish that ignorance is the cause of samsāra. From the verse 13rd-21st , ācārya get in to the topic of the cause of samsāra and its solution. Topic of creation is also being covered to answer where is the delusion come from.
śaktidvayaṃ hi māyāyā vikṣepāvṛtirūpakam । vikṣepaśaktirliṅgādi brahmāṇḍāntaṃ jagat sṛjet II 13 II
Indeed, Maya has two powers of the nature of projecting and veiling. The projecting power, beginning from the subtle body (the experiencer) to the total universe (the experienced), creates the world.
sṛṣṭirnāma brahmarūpe saccidānandavastuni । abdhau phenādivat sarva nāmarūpaprasāraṇā II 14 II
Reality in name and form is called Creation. Existence-Consciousness-Bliss, is the entity in which, like foam in the ocean, all names and forms are manifested.
To understand the process of creation, we need to see the verse 14th first, then verse 13rd.
Brahman with the nature of sat-cit-ānanda is pointed out as the cause of the universe. If not from the entity which is having the nature of consciousness-existence-limitless, the the endless varieties of creation is not possible. In the same time the plurality world is seems impossible created from a non-duality conscious being. Therefore the impossible is made possible because of māyā alone.
Māyā is always being brought in to the topic of creation. Even though everything here is having Brahman-Consciousness as the source, but without māyā, everything here is never come in to being. We need to know how is this experiential world come in to being, which we usually called as creation. Let us understand what is the meaning of creation first. If we say "a pot is created", means a production of an effect (pot) from the cause (clay) is happened. Clay is said to be the cause, and the earthenware like pot, plate, etc. are said to be the effect. We say that the potter has produced the earthenware. But when we analyse about the production, is the potter really produce or create anything? In fact, nobody can really create a thing. Matter can never be created or destroyed. The potter is just bringing the form of pot out of clay. Even the form of the pot itself can not say to be the creation of the potter, the pot's form in the clay was in un-manifest state, now being bring into the being by the potter in to a clay pot. Therefore the meaning of creation is nothing just adding a shape into the already existing clay. Pot, plate, etc. are just a name and form (with its function) - nāma-rūpa given to the clay. Clay plus name and form equals to earthenware. Gold plus name and form equals to golden ornament. Consciousness plus name and form equals to this manifestation. Un-manifest name and form is called māyā. Clay with the un-manifest name and form is the cause, on the other hand clay with the manifest name and form is the effect (earthenware). Brahman-Consciousness with the un-manifest name and form māyā is the cause, and Brahman-Consciousness with the manifest name and form māyā is the effect which is called creation.
Māyā is said to be power - śakti of Brahman is not a different entity apart from Brahman, just like one's power of speech is not apart from that person. And this power is of two folds - śaktidvayaṃ vikṣepāvṛtirūpakam, one is of the nature of veiling - āvarana-śakti and another one is of the nature of projecting - viksepa-śakti. When the projecting power is operating, all the un-manifest name and form gets manifested. The entire universe and individual jīva are come into being - vikṣepaśaktirliṅgādi brahmāṇḍāntaṃ jagat sṛjet. In the very same time the veiling power of māyā is operating, therefore jīva is ignorant about his/her true nature. Because of this veiling power, māyā is also called as ajñānam - ignorance. And this ignorance about the non-dual nature of the Self, causing the individuality - I-ness (because of identification with the name and form projecting by the same māyā). Because of the I-ness, one is always seeking to fill up the (false) limitation of one self, therefore ignorance is said to be the cause of samsāra.
Just like in the ocean, water as the only substance which is never undergo any change, manifest as waves, froth, bubbles, etc. Waves etc are only name and form. If we don't see the name and form, they are water alone.