Many people claim that as per many scholarly studies and references, "purush sukta in Rigveda is an interpolation"
Can somebody provide references to such scholarly studies and references ?
In general the tenth mandala of Rig Veda is late. The Sanskrit has shed many Indo-European elements of Vedic Sanskrit and looks more like Paninean Sanksrit. While early mandalas are simple hymns to personifications of nature, the tenth mandala has pantheistic speculation which would develop further in Hinduisms later.
Many scholars consider Purusha Sukta an interpolation.
Scholars also do agree that there are certain interpolations and corruptions in Rig Veda. This only will mean that while final codification, divisions and rearrangements of the hymns and verses of the Rig Veda, some portion was freshly inserted while some was removed. We start finding tropical Seasons, animal, plant, agricultural instrument references along with flora-fauna appearing in Rig Veda only because of this. Of interpolation purushasukta is a fine example, which, beyond doubt, has been proved to be the interpolation of far later times.
Max Muller states:
There can be little doubt, for instance, that the 90th hymn of the 10th book (Purusha Sukta) is modern both in its character and in its diction. ( ... ) It mentions the three seasons in the order of the Vasanta, spring; Grishma, summer; and Sarad, autumn; it contains the only passage in the Rigveda where the four castes are enumerated. The evidence of language for the modern date of this composition is equally strong. Grishma, for instance, the name for the hot season, does not occur in any other hymn of the Rigveda; and Vasanta also does not belong to the earliest vocabulary of the Vedic poets."
That remarkable hymn (the Purusha Sukta) is in language, metre, and style, very different from the rest of the prayers with which it is associated. It has a decidedly more modern tone, and must have been composed after the Sanskrit language had been refined, and its grammar and rhythm perfected."
The Purushasukta upholding four varnas is a later composition added to the original Rig Veda. It is evident from the language of the Sukta as compared with the language of the rest of the Rig Veda. That it is later production, is the opinion of all scholars. In support of this argument, Dr. Ambedkar quotes Coleebrook:
That the remarkable hymn (the Purusha Sukta) is in language , metre, and style very different from the rest of the prayers with which it is associated. It has a decidedly more modern tone and must have been composed after the Sanskrit language had been refined and its grammar and rhythm perfected. The internal evidence it furnishes serves to demonstrate the important fact that the compilation of the Vedas in their present arrangement took place, after the Sanskrit tongue had advanced from the rustic and irregular dialect in which the multitude of hymns and prayers of the Veda was composed to the polished and sonorous language in which the mythological poems, sacred and profane (Puranas and Kavyas) have been written". The Purusha Sukta which is considered to be the nucleus of Rig Veda and the philosophy of Brahmanism has not been included in the beginning or in the middle portion of Rig Veda but only at the fag end. Similarly the sum total of the ideas of Mahabharata is Bhagavat Gita. It has also been included only as an appendix to Mahabharatha. These things show that these were later interpolations to fulfill the heinous aims of Brahmanism.
The Purusha Sukta occurs also in the Atharva Veda as the supplementary part. If it was the earliest composition why should it have been placed in such an inconsequential collection. It means that it was only a later interpolation in Veda with crooked intentions. The Purusha Sukta is a forgery by the Brahmins to bolster up their claim to superiority. Dr. Ambedkar is of opinion that the Brahmins had forged the Purusha Sukta at least the two verses 11 and 12 at some later stage, a long time after the fourth varna had come into being with a view to giving the system of Chathurvarnya, the sanction of the Veda.
G. N. S. Raghavan in Discovering the Rigveda discusses verses 11 and 12:
Purusha Sukta An Interpolation
In order to confer legitimacy on the caste system with its hereditary and graded inequality, the high priests of Brahminism who acted as thought moulders interpolated hymn no. 90, known as the Purusha Sukta, in the last mandala (Book X) of the Rigveda. This poem proclaims that the scheme of Chatur Varna (Four Orders of Society) originated from the immolation of a primal being in the sacrificial fire. Verses 11 and 12 of the hymn, which has a total of 16 verses, are in the form of question-and-answer. The rest of the poem is narrative. They read as follows:
When they divided Purusha how many portions did they make? What do they call his mouth, What do they call his thighs and feet?
The Brahmin was his mouth, of both his arms was the Rajanya made. His thighs became the Vaisya, from his feet the Sudra was produced.
If we retain the leading question in verse 11 but omit the Brahminist answer in verse 12, the poem will be like many another Rigvedic hymn expressing wonder at the mystery of the universe and attempting an imaginative, metaphorical explanation of its origin.
Verse 13 and 14 read:
The moon was born from his mind, The sun arose from the eye, Indra and Agni from the mouth, wind arose from his vital breath.
The mid-region came from his navel, The sky came from his head, The earth from his two feet, The quarters from the ear —
Thus they set the worlds in order.
This is an unexceptionable hazarding of a poetic guess. The mischief is in verse 12. The significance of the anatomical detail is explained in a Brahmana passage of the Yajurveda: "The part of man above the navel is pure; that below is impure" (Sahitya Akademi's Anthology, Vol. I, p. 147). It sets out the Chatur Varna scheme which forms the bedrock of the Brahminical social system. The four orders or major castes proliferated over time into hundreds of regional castes and sub-castes in a complex system of graded inequality.
The doctrine that high and low occupations are fixed by the caste of one's birth is wholly alien to the ethos of the Rigveda. It was not to be expected that Indian Vedic scholars would be troubled by this inconsistency, steeped as they have been in the belief that the Veda is of divine origin, the rishis having merely put into verse what was 'revealed' to them.