But the word "Incarnation" and the defined doctrine thereof, came after a lot of study and reflection of such things.
There were, after all, other opinions. One opinion was that Jesus Christ was two persons ---Jesus was one person, and the Christ another--- so that Jesus was a human person whose body was "possessed" by another person, God ("I'm your vehicle.")
And those who said Jesus had only one nature, the Divine Nature, and that his humanity was a kind of elaborate disguise. Still others said that Jesus was the first-created, not the only-begotten. And so forth.
This all sounds wacky to us now, but the proponents of these positions found their own Scriptural proof-texts, which seemed like a good idea to them at the time.
The truth of the Incarnation is rooted in the Scripture you cite. The defined doctrine of the Incarnation --- in all its details --- was articulated much later.
Fair enough.