Library Eusebius of Caesarea Life of Constantine
Book 1, Chapter 20: Flight of Constantine to his Father because of the Plots of Diocletian.
The emperors then in power, observing his manly and vigorous figure and superior mind, were moved with feelings of jealousy and fear, and thenceforward carefully watched for an opportunity of inflicting some brand of disgrace on his character. But the young man, being aware of their designs, the details of which, through the providence of God, more than once came to him, sought safety in flight; in this respect again keeping up his resemblance to the great prophet Moses. Indeed, in every sense God was his helper; and he had before ordained that he should be present in readiness to succeed his father.
English translation by Ernest Cushing Richardson, in Nicene and Post-Nicene Fathers, Series II, Vol. I (eds. Philip Schaff and Henry Wace; Buffalo: Christian Literature Publishing Co., 1890). Public domain. Digital text via New Advent Church Fathers.