As for the claim that it derives from nisyān (forgetfulness), that a human being is called insān because he forgets, and that people are likewise called nās because they forget, this view has no merit. What connection is there between nisyān, whose root is n-s-y, and nās, whose root is n-w-s? Likewise, what connection does it have with uns, whose root is ʾ-n-s?

Insān follows the pattern fiʿlān, from ʾ-n-s. Its final alif and nūn are additional letters; no other analysis is possible. For there is no word ansana in their language from which insān could be formed on the pattern ifʿāl. Nor can its initial alif and nūn both be additional, since the pattern infaʿl does not occur in their language. It must therefore follow the pattern fiʿlān, from uns.

Since the pattern infaʿl does not occur in their language, it must follow the pattern fiʿlān, from uns.

Had it been derived from nasiya (to forget), it would have been nisyān, not insān.

You may ask: “Why not take it as following the pattern ifʿilāl, with its original form being insiyān, like the expression laylah idhiyān (a moonlit night), and then suppose that the yāʾ was omitted for ease of pronunciation, producing insān?”

I reply: This is precluded by the absence of the pattern ifʿilāl from their language, the omission of the yāʾ without any cause, and the assertion of a formation without parallel. All of this is unsound. Moreover, it has been said that nās was originally unās: the hamzah was omitted, producing nās. The following verse is cited as evidence:

“Death comes upon people unawares.”

There is no doubt that unās follows the pattern fuʿāl; no other analysis is possible. If nās was originally unās, this is the strongest evidence that it derives from ʾ-n-s. Nās would then have precisely the same derivation as insān.

According to this view, nās has the pattern ʿāl, since its first radical has been omitted.

According to the first view, its pattern is f-ʿ-l, because it derives from naws.

According to the weak view, its pattern is f-l-ʿ, because it derives from n-s-y: its third radical was transposed into the position of the second, producing nās on the pattern f-l-ʿ.