"“ That the Purusha Sukta, considered as a hymn of the Rig Veda, is among the latest portions of that collection, is clearly perceptible from its contents. The fact that the Sanaa Samhita has not adopted any verse from it, is not without importance (compare what I have remarked in my Academical Prelections). The Naigeya school, indeed, appears (although it is not quite certain) to have extracted the first five verses in the seventh prapathaka of the first Archika, which is peculiar to it.”"
January 1, 1970
https://en.wikiquote.org/wiki/Purusha_Sukta