Luke 24:19

‘And he said to them, “What things?” And they said to him, “The things concerning Jesus the Nazarene, who was a prophet mighty in deed and word before God and all the people,”

To this the Stranger asked, ‘What things?' And that caused the dam to burst and it all poured out. Luke 24:21 need to be read as one in order to see how they hurried on from one idea to another in a typical outburst of feeling. They read precisely like the words of people who had been under constraint, as they gabbled out one idea after another, including ideas which the Stranger could not possibly have known about. They just could not keep it in any longer. Notice the ‘they'. The point is that there were two witnesses.

They firstly described Who Jesus was from a Jewish, pre-resurrection point of view. He was Jesus the Nazarene, who was a prophet mighty in deed and word in the eyes of both God and man. Jesus was very much seen as a great prophet by His followers (see Luke 4:16; Luke 7:16; Luke 9:7; Luke 9:18; Luke 13:31). They could still see Him in their mind's eye as He stood in the Temple courtyard, or on the mountainside, outstanding in the power of His preaching. They could still see Him walking among the sick and demon possessed, laying His hands on those who were diseased and healing all of them, and casting out evil spirits with a word of power. So they had every reason for thinking of Him as a prophet, for that is how Jesus had described Himself. He had revealed Himself as the anointed Prophet of Isaiah 61:1 (Luke 4:17). He had declared that it was the failure to hear His preaching as the One Who was greater than Jonah and Solomon that condemned the current generation (Luke 11:31). He was seen as the great Prophet like to Moses (Acts 3:22). He was God's Servant, fulfilling the promises concerning the Servant in Isaiah (Matthew 8:17; Matthew 12:18; Acts 4:30). He was the Prophet Who must not die outside Jerusalem (Luke 13:33).

The unusual word used for ‘Nazarene' (Nazarenou as in p75, Aleph, B, etc) serves to confirm that Luke is citing a source.