The first occurrence.
And God said, Let there be a firmament in the midst of the waters, and let it divide the waters from the waters. Gen 1:6
The primitive root.
resh ר = the head of man, thus head, first, top, beginning, man
quph ק = sun on the horizon, thus condense, circle, time
ayin ע = the eye, thus watch, know, shade
The story: Overspread (resh, in the sense of top or above) as far as (quph, in the sense of horizon) the eye can see (ayin).