I don’t believe that this gesture by Jesus is meaningless just because there haven’t been any thoughts about it the Church has been willing to join it’self to. There is way too much going on and besides I can’t imagine Jesus doing anything insignificant especially during moments like this one. St John seems to purposely point out the bodily movements of Jesus while this was happening. Also Jesus wasn’t hap hazardly doodling when this came up. He deliberately began doing that at the onset of this confrontation.
I believe Jesus was acting as prophet when this happened. Just as the OT prophets propheciedt with their bodies the role of the nation or of God, Jesus recognized the pattern of salvation history in this event. The woman accused of adultery represents the Jews ( adultress) past,present and future who become the(spotless bride) Church. The accusers represent the Jews become all those who will accuse and persecute the Church in the future, especially of adultery.
The writing on the ground gesture was a sign of the Sacred texts .
from the DRB:
And this they said tempting him, that they might accuse him.
But Jesus bowing himself down, wrote with his finger on the ground. *
Lowerings and liftings are often significant gestures. Jesus bowing down can mean Himself writing in the Apostles. It could point to the writing of the OT.
When therefore they continued asking him,
he lifted up himself, and said to them: He that is without sin among you, let him first cast a stone at her. *
This can mean alot of things in this line of thinking. Since Jesus began writing when they began speaking it seems to me that they might have been attentive to what was being written. St John seems to attest to this by writing the phrase I underlined. Their hearts weren’t penetrated by seeing what Jesus was writing in the sand.
And again stooping down, he wrote on the ground.
9 But they hearing this, went out one by one, beginning at the eldest. *
It was in hearing the Word that they were disarmed. Yet Jesus continued writing in the sand.
The parting of the eldest to the youngest could be viewed as a living archetype of time.
Note that He stoops or bows down to write and lifts Himself up to speak.
And Jesus alone remained, and the woman standing in the midst. 10 Then Jesus lifting up himself, said to her: Woman, where are they that accused thee? Hath no man condemned thee?
This is of course would be a picture of the Church in of it’self. Jesus lifting up Himself and the Church Triumphant.