from the expressions jannahu al-layl and ajannahu, meaning “the night concealed him.” Likewise, ajanna al-mayyit means to conceal the deceased in the earth.
The poet said:
“Do not weep for any dead after the one
Whom Alī, Abbās, and Abū Bakr’s family buried.”
He means the Prophet (may Allah bless him and grant him peace). From the same root comes janīn (fetus), because it is concealed in its mother’s womb. Allah Most High says:
“And when you were fetuses in your mothers’ wombs” (53:32).
Likewise, mijann (shield) derives from this root, because a warrior conceals himself behind it against his opponent’s weapons; as does jannah (garden), because its trees conceal anyone within it. The same applies to junnah—with a u-vowel—meaning anything that protects a person from arrows and weapons, and to majnūn (insane), because the person’s reason is concealed.
As for nās (mankind), it is related to ins (humankind) in both wording and meaning. Their relationship is one of intermediate derivation: the different permutations of a word’s root are united by a single meaning.
Both ins (humankind) and insān (human being) derive from īnās, meaning seeing and perceiving. An example is His statement:
“He perceived a fire on the side of the Mount” (28:29),
meaning that he saw it. Another is:
“If you perceive sound judgment in them” (4:6),
meaning that you perceive and observe it.
A human being is therefore called insān because he is perceived—that is, seen with the eye. There are two views concerning nās.
The first is that it is formed by rearranging the root a-n-s. This is unlikely, since the default assumption is that no rearrangement has occurred.
The second—and correct—view is that it derives from naws, meaning continuous movement. People are thus called nās because of their outward and inward movement, just as a man is called Hārith (one who labors) and Hammām (one who forms intentions). These are the truest names, as the Prophet (may Allah bless him and grant him peace) said:
“The truest names are Hārith and Hammām.”
For everyone has intention and will, which are the starting point, and labor and action, which are the endpoint. Everyone is therefore a Hārith and a Hammām. Labor and intention are outward and inward movement, which is precisely what naws means.
Nās derives from n-w-s: the wāw bore a vowel and was preceded by a short a, so it changed into an alif.
These are the two well-known views concerning the derivation of nās.