The first occurrence.
And the earth brought forth grass, and herb yielding seed after its kind, and the tree yielding fruit, whose seed was in itself, after its kind: and God saw that it was good. Gen 1:12
The primitive root.
Strong’s H3318 יצא yatsa, a primitive root meaning, “to go out, to go forth.” The 3-letter root is yud + tsadey + aleph.
yud י = the closed hand, thus work, throw, worship
tsadey צ ץ = the trail, thus a man concealed, journey, chase, hunt
aleph א = the ox head, thus strength, power, leader
The cognate word “excrement” is the key to unlock the parable. The man enclosed (yud, as something done privately) squats down (tsadey, as a man on a trail squats down to conceal himself from the prey), and, by the strength of his core (aleph) causes his excrement to issue forth.