"“ 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 internal evidence which 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.”"
January 1, 1970
https://en.wikiquote.org/wiki/Purusha_Sukta