Greco-Roman Period
Lawrence H. Schiffman, From Text to Tradition, Ktav Publishing House, Hoboken, NJ, 1991.

The history of virtually every aspect of halakhah discussed here conforms to a pattern. In
the tannaitic period adjustment to the absence of the Temple took place, and then, in
amoraic times, the ritual or law was given significance as a replacement for the Temple.
The most significant example of the transition from Temple to non-Temple Judaism is
that of Torah study. For the rabbis, study replaced sacrifice as a form of worship
alongside prayer.

The modes of study in tannaitic and amoraic times have already been sketched in an
earlier chapter. Here we must reflect on the function of study. When the Temple ritual
was still in effect, study was seen as a way of knowing God’s commands and word. In
this sense it was a cognitive experience, designed to open up the world of revelation to
contemporary Israel, a pattern evidenced among the various groups of Second
Commonwealth times. Once sacrifice and the other Temple-centered rituals were no
longer possible, study gradually became an act of worship. In tannaitic times, Rabbinic
Judaism concentrated on its own students and teachers. In the amoraic period, however,
when it became a mass movement seeking to gain the adherence of all Jews, it steadily
popularized the idea that Torah study was an act of worship, ultimately making it central
to the whole of Jewish life.