An online dictionary says an ‘object lesson’ is:
1. A concrete illustration of a moral or principle.
2. A lesson taught by using a material object.
Bread and wine had been part of the Passover ceremony for one and a half thousand years. When Jesus picked up the bread on that night, broke it and said “Take and eat; this is my body.” – there would have been a bunch of recognitions and connections going off in the disciples minds.
This was not the first time He referred to Himself as Bread…
Perhaps they remembered the time that He said “…I am the bread of life… But here is the bread that comes down from heaven, which anyone may eat and not die. I am the living bread that came down from heaven. Whoever eats this bread will live forever. This bread is my flesh, which I will give for the life of the world.” And then he took a cup, and when he had given thanks, he gave it to them, saying, “Drink from it, all of you… This cup is the new covenant in my blood, which is poured out for you…”
(This little series has been posted with dates in the opposite order to which it was written so as to appear sequentially to readers)