Why God placed man in the Paradise with a twofold object, namely, that he might both till it and keep it, when the Paradise was in reality in need of no cultivation, because it was perfect in everything, as having been planted by God; nor, again, did it require a keeper, for who was there to ravage it? (Genesis 2:15).
The Midrash of Philo 15:1
The Midrash of Philo 15:1