From the early Church Fathers to now.
“And the children of Israel set forward from Ramesse to Socoth, being about six hundred thousand men on foot, beside children.”
“Joseph came into Egypt alone, and soon thereafter six hundred thousand depart from Egypt. What is more marvelous than this? What greater proof of the generosity of God, when from persons without means he wills to supply the means for public affairs?”
“From their single ancestor, in not much more than four hundred years, the Hebrew people became so numerous that at the time of the exodus from Egypt there were, we are told, six hundred thousand men of military age. This number does not include the Idumeans, who were not reckoned with the people of Israel, although they were descended from Israel's brother Esau, who was a grandson of Abraham. Nor does it include those other descendants of Abraham who were not of the line of his wife Sarah.”
The in-app commentary runs from the Fathers to the early-modern record, then stops — that's where the public-domain sources end, not where the reading does. For the modern reading, follow the sources directly.