Is Purusha (mentioned in Purusha suktam) same as Brahman (Parabrahman) ?
Is Purusha (mentioned in Purusha suktam) same as Brahman (Parabrahman)?
Yes, he is.
The Purusha is described as the origin of the universe, the elements, all the Devas, all the worlds, and everything in creation:
tasmAt virAd ajAyata
From the Purusha was born the universe.
He is also described as the being whom if a person knows, that person attains moksha:
vedAhametam purusham mahAntam Aditya varNam tamasaH parastAt | tam evam vidvAn amRta iha bhavati na anyaH panthA vidyate 'yanaaya ||
I know this great Purusha who is brilliant like the sun and beyond all darkness. He who knows him thus, attains immortality in this very birth. I know of no other way to salvation.
And according to the Brahma Sutras, which are a summary of the teachings of the Upanishads, Brahman is the origin of the world:
2. (Brahman is that) from which the origin, &c., of this (world proceed).
Brahman is also the object of meditation for moksha:
7. Because release is taught of him who takes his stand on it.
So based on the Purusha in the suktam having the same characteristics as Brahman, it is concluded that the Purusha is none other than Brahman.
Purusha Sukta appears in 10th Mandala.
Many scholars inferred that both 1st and 10th Mandalas of Rig Veda, compared to 2nd to 7th Mandalas - the oldest part of the Rigveda, are younger.
So the content in those 1st and 10th Mandalas is large (2006 and 1754 mantras respectively), compared to 2 to 7 Mandalas. Further, the expression of ideas also changes, in my view, from 2 to 7 Mandalas to 1st and 10th Mandalas.
Let us examine Rig Veda 2.1.2 and subsequent mantras in the same Hymn, dedicated to Agni and wherein the expression of Brahman was used.
तवाग्ने होत्रं तव पोत्रं रत्वियं तव नेष्ट्रं तवमग्निद रतायतः | तव परशास्त्रं तवमध्वरीयसि बरह्मा चासि गर्हपतिश्च नो दमे ||
Thine is the Herald's task and Cleanser's duly timed; Leader art thou, and Kindler for the pious man. Thou art Director, thou the ministering Priest: thou art the Brahman, Lord and Master in our home.
(Even H.H. Wilson translated the word बरह्मा as BRAHMAN.)
Here, Agni was eulogised as BRAHMAN. In the subsequent mantras, Agni was declared to be Indra/Vishnu/Brahmaṇaspati/Varuna/Mitra/Rudra, etc. However, Yama and Garuda/Garutman were not mentioned.
In Rig Veda 2.1.4, Varuna was eulogised as Law protector - *Agni, thou art King Varuṇa whose laws stand fast; which was in later period attributed to Yama - dharma devata, protector of Dharma.
In Rig Veda I.164/46, dedicated to Viśvedevas, mention was made about Yama and Garuda/Garutman.
They call him Indra, Mitra, Varuṇa, Agni, and he is heavenly nobly-winged Garutmān. To what is One, sages give many a title they call it Agni, Yama, Mātariśvan.
Yama is mentioned roughly fifty times in the Rig Veda, almost exclusively in the first and (far more frequently) in the tenth book. Four hymns (10.10, 10.14, 10.135, and 10.154) are directly addressed to or about Yama.
So there was a definite shift in ideas from Madala 2, which was the Oldest, to Mandala 1 or 10, which was the younger one.
Coming to the question of Is Purusha (mentioned in Purusha suktam) same as Brahman (Parabrahman) ?, in my opinion, the ideas are different.
In Purusha Sukta, it was narrated as everything, including Indra, Agni, Vayu, etc, emanated from Purusha. Further, the division of humans into 4 Varnas was mentioned here. It closely resembles eulogisation of Vishnu/Shiva/Shakti, etc, in Puranas as SUPREME GOD, through which everything emanated.
So we can observe that a shift in ideas here compared to RV 2.1.2, wherein Agni was declared as BRAHMAN itself.