Luke 1:2

2 just as they were handed down to us by those who from the first were eyewitnesses and servants of the word.

Read Luke 1:2 Using Other Translations

Even as they delivered them unto us, which from the beginning were eyewitnesses, and ministers of the word;
just as those who from the beginning were eyewitnesses and ministers of the word have delivered them to us,
They used the eyewitness reports circulating among us from the early disciples.