Job 28:21 KJV

Seeing it is hid from the eyes of all living, and kept close from the fowls of the air.

fowls a bird Still heard today: waterfowl, ducks, geese, and other water birds Webster’s 1828 · Fowl

What these words mean in the King James Bible, and where you’ll still hear them today.

Wisdom is the gift of GodThere is a two-fold wisdom; one hid in God, which is secret, and belongs not to us; the other made known by him, and revealed to man. One day's events, and...

Psalms 49:3–4 My mouth shall speak of wisdom; and the meditation of my heart shall be of understanding. …
Matthew 11:25 At that time Jesus answered and said, I thank thee, O Father, Lord of heaven and earth, because thou hast hid these things from the wise and prudent, and hast revealed them unto babes.
Matthew 13:17 For verily I say unto you, That many prophets and righteous men have desired to see those things which ye see, and have not seen them; and to hear those things which ye hear, and have not heard them.
Matthew 13:35 That it might be fulfilled which was spoken by the prophet, saying, I will open my mouth in parables; I will utter things which have been kept secret from the foundation of the world.
1 Corinthians 2:7–10 But we speak the wisdom of God in a mystery, even the hidden wisdom, which God ordained before the world unto our glory: …
Colossians 2:3 In whom are hid all the treasures of wisdom and knowledge.

From OpenBible.info, most relevant first.

Seeing it is hid וְנֶעֶלְמָה wĕneʿelmâ עָלַם Verb · niphal perfect, third person feminine singular · with and
from the eyes מֵעֵינֵי mēʿênê עַיִן Noun · masculine or feminine dual construct · with preposition
of all living כָל kol Noun · masculine singular construct חָי ḥāy חַי Adjective · masculine singular
and kept close נִסְתָּרָה nistārâ סָתַר Verb · niphal perfect, third person feminine singular
from the fowls וּמֵעוֹף ûmēʿôp עוֹף Noun · masculine singular construct · with and, preposition
of the air הַשָּׁמַיִם haššāmayim שָׁמַיִם Noun · masculine plural · with the

Notes, marks, and bookmarks on this verse are in the KJV Bible app.