Another matter: “These are the words” – Rabbi Tanḥuma said: To what is the matter comparable? It is to a person who was selling purple wool and was proclaiming: ‘Here is purple wool.’ The king peered and heard his voice. He called him and said to him: ‘What are you selling?’
He said to him: ‘Nothing.’ He said to him: ‘I heard your voice, you were saying: Here is purple wool, and you say: Nothing?’ He said to him: ‘My master, truth is that it is purple wool, but for you it is nothing.’13Purple wool was considered a luxury item. The seller was saying that he was announcing to the masses that he had purple wool, but it was not of a quality worthy of a king, and therefore to the king he said that he had nothing (Etz Yosef).
So, Moses, before the Holy One blessed be He, who created the mouth and speech, he said: “I am not a man of words” (Exodus 4:10). But with Israel, it is written in his regard: “These are the words.”