"Classical sources" is an incredibly broad topic. It is easy to simply say that you are drawing from Jewish tradition through classical sources, but the breadth and depth of those sources is often unfathomable. In an attempt to better organize our classical sources on conversion, we have broken them out by Time period, and below each text we have suggested categories and Source Type.
Our attitudes toward conversion have been shaped in large part by three important halakhic works. Below are excerpts from the Mishneh Torah, the Shulhan Arukh, and Maskhet Gerim.
From Abraham to Ruth conversion has always been a central trope in biblical literature. This section has most of the quotes from the biblical text relating to conversion. These texts are the foundations on which other later authors built their attitudes toward converts and conversion.
The Second-Temple Period was quite a prolific period for new texts in the Jewish community. The Pseudepigrapha, the Apochrypha, the writings of Flavius Josephus, Philo and the Dead Sea scrolls are just some of the various texts that came out of this time period. This section contains texts that deal with the convert in Second-Temple period.
This section comprises texts spanning from the Mishnaic Period until the start of the Geonic period. It includes texts from the Talmud, and various Midrashic collections. One will notice here significant diversity of opinion about the nature of conversion in Judaism.
This section deals with commentary and codes from the medieval period. Each commentator brings his own unique reading of rabbinic tradition. Taken together, these texts offer a wide diversity of opinion surrounding issues of conversion.
This section includes ideas of modern thinkers about conversion. While most of these thinkers are no longer living, their rulings and writings have shaped much of what we believe today about conversion.
While we have so much to learn from our history, we are still, as Rabbi David Ellenson, President of HUC-JIR, likes to say, "Dwarves standing on the shoulders of Giants." Standing on the shoulders of the Bible, the Rabbis, and medieval thinkers, these contemporary thinkers have a great deal to add to our understanding of outreach and conversion.