Though his work the Sefer ha-Chinuch (Book of Education) was well known, having been repeatedly commented on and republished in more than a dozen editions, it was reserved for Rosin to discover anything accurate concerning the personality of the author.
The book itself is anonymous; and the statement by Gedaliah ibn Yaḥyah (dating from the middle of the sixteenth century), that its author was the celebrated Talmudist Aaron ben Joseph ha-Levi, has been generally accepted.
The Sefer ha-Chinuch is an enumeration of the six hundred and thirteen affirmative and negative precepts of the Mosaic Law, arranged in the order of the weekly lessons (parashot), with their ethical and halakic aspects, based upon rabbinical tradition of the Talmudic and post-Talmudic periods, for which latter feature he relies upon Alfasi, Maimonides, and Naḥmanides as main authorities.
His chief and original merit is displayed in the ingenuity and religious fervor with which he dwells upon the ethical side of the Law, avoiding most admirably all abstruse philosophical and mystical theories, such as are only too abundant in his guides, Maimonides and Naḥmanides.
When we therefore treat considerately even the animals given for our use, and withdraw not from them some of the fruits of what their labor obtains for us, we educate our soul thereby to be all the kinder to our fellow men, and accustom ourselves not to withhold from them what is their due, but to allow them to enjoy with us the result of that to which they have contributed" (par.
Even in the citation of rabbinical traditions and amplifications of the Law, the author displays rare judgment and proper feeling, thus completely justifying the popularity which this book has for centuries enjoyed.
Compared with the familiar principles of faith as enumerated by Maimonides, one is struck by the fact that the Sefer ha-Chinuch, representing the official orthodoxy of the time, mentions neither the unchange-ableness of the Law nor resurrection.