In the New Testament the word stenographer (or stenography) does not occur. How do we know they were at work in Jesus’s ministry?

The answer is in the foundational texts. They are clear that rapid writers were responsible for the preservation and deliverance of the spoken word of Jesus. We put these texts together in word for word translations.

Luke
^“1Inasmuch as many have undertaken to compile an account of the things accomplished among us, ²just as delivered to us the eyewitnesses from the beginning also being servants of the spoken word,”
Luke 1:1-2

The things are the Jesus events, and eyewitnesses were at work during the spoken word as “servants of the spoken word”. They delivered information to us, the bystanders. As servants of the spoken word it was only possible to deliver by writing, note taking. Oral tradition was not possible during the spoken word of the Jesus events. Us in verse 1 is us in verse 2.

 
Paul
“³How shall we escape if we neglect so great salvation; which beginning to be spoken by the Lord, was established in behalf of us, by those who were hearing; ⁴God also bearing witness, both with signs and wonders, and with divers miracles, and gifts of the Holy Ghost.”
Hebrews 2:3-4

Hearers of the Lord were busy with establishing for future generations what they heard, while miracles occurred. Can it be more clear?

John
“³That which we have seen and heard we proclaim also to you, so that you may have fellowship with us; … ⁴And we are writing these things that our joy may be complete.
1 John 1:3-4

The apostle John is saying here that they made known what they had seen and heard. They did so in writing, and they did so from the very first. Why? It was part of the joy of the Gospel.

Apostolic claims
We have in these three foundational texts convincing statements that the apostles brought out the spoken words of Jesus, they had preserved during his ministry. And there is no reason to doubt their claims.

Orations
In each of the four Gospels there are long orations of Jesus. We know he spoke in Greek (see a future blog), and there was only one way in this language to preserve orations: stenography. An oration is not the same as a dictation to a secretary. Orations in public could only be preserved by means of stenography (Seneca). It was the only tool that was in use in the Roman Empire for this purpose. It had been developed exclusively for it. And in the first century it was practiced in the lower social layers of society: slaves and ordinary people, who were trained in the new art of writing (Plutarch).

Jesus said
More than 600 times it is mentioned in the Gospels: Jesus said … How is it possible, for Heaven’s sake, that theologians have cast doubts on Jesus’s sayings for centuries until today, with their claim of the oral tradition behind the Gospels? And without any sound proof for it! There is a better story to tell, the story of Documentation during Jesus’s ministry.

And yet, ordinary Christians have always believed. Their experience was and is the power of Jesus’s words. Their simple creed was and is: Listening to his words, is listening to Him.