Eusebius Ecclesiastical History 2.18

1. Copious in language, comprehensive in thought, sublime and elevated in his views of divine Scripture, Philo has produced manifold and various expositions of the sacred books. On the one hand, he expounds in order the events recorded in Genesis in the books to which he gives the title Allegories of the Sacred Laws; on the other hand, he makes successive divisions of the chapters in the Scriptures which are the subject of investigation, and gives objections and solutions, in the books which he quite suitably calls Questions and Answers on Genesis and Exodus.
2. There are, besides these, treatises expressly worked out by him on certain subjects, such as the two books On Agriculture, and the same number On Drunkenness; and some others distinguished by different titles corresponding to the contents of each; for instance, Concerning the Things Which the Sober Mind Desires and Execrates, On the Confusion of Tongues, On Flight and Discovery, On Assembly for the Sake of Instruction, On the Question, 'Who is Heir to Things Divine?' or On the Division of Things into Equal and Unequal, and still further the work On the Three Virtues Which With Others Have Been Described by Moses. 3. In addition to these is the work On Those Whose Names Have Been Changed and Why They Have Been Changed, in which he says that he had written also two books On Covenants.
4. And there is also a work of his On Emigration, and one On the Life of a Wise Man Made Perfect in Righteousness, or On Unwritten Laws; and still further the work On Giants or On the Immutability of God, and a first, second, third, fourth and fifth book On the Proposition, That Dreams According to Moses are Sent by God. These are the books on Genesis that have come down to us.
5. But on Exodus we are acquainted with the first, second, third, fourth and fifth books of Questions and Answers; also with that On the Tabernacle, and that On the Ten Commandments, and the four books On the Laws Which Refer Especially to the Principal Divisions of the Ten Commandments,and another On Animals Intended for Sacrifice and On the Kinds of Sacrifice,and another On the Rewards Fixed in the Law for the Good, and on the Punishments and Curses Fixed for the Wicked.
6. In addition to all these there are extant also some single-volumed works of his; as for instance, the work On Providence, and the book composed by him On the Jews, and The Statesman; and still further, Alexander, or On the Possession of Reason by the Irrational Animals. Besides these there is a work On the Proposition that Every Wicked Man is a Slave, to which is subjoined the work On the Proposition that Every Good Man is Free. 7. After these was composed by him the work On the Contemplative Life, or On Suppliants, from which we have drawn the facts concerning the life of the apostolic men; and still further, the Interpretation of the Hebrew Names in the Law and in the Prophets are said to be the result of his industry. 8. And he is said to have read in the presence of the whole Roman Senate during the reign of Claudius the work which he had written, when he came to Rome under Caius, concerning Caius' hatred of the gods, and to which, with ironical reference to its character, he had given the title On the Virtues. And his discourses were so much admired as to be deemed worthy of a place in the libraries.