The first occurrence.
And God called, with regard to the light, Day, and with regard to the darkness, He called Night. And there was evening and there was morning, one day. Gen 1:5
The primitive root.
Strong’s H1242 boqer, a concrete noun meaning, “morning;” from Strong’s H1239 בקר baqar, a primitive root meaning, “to break open.” According to the Ancient Hebrew Lexicon, the bet was transposed from an original pey, making the 3-letter root is pey + quph + resh.
pey פ, ף = the mouth, thus open, blow, scatter, edge
quph ק = sun on the horizon, thus condense, circle, time
resh ר = the head of man, thus head, first, top, beginning, man
The story: The opening (pey) of the sun on the horizon (quph) at the beginning (resh) of the day.