What did Jesus think about Jewish practice regarding impurity? How did he relate to the inner-Jewish debates of his day concerning ritual purity and impurity? Did he discard the impurity concept altogether, or was it an obvious and natural part of his Jewish faith and life? Did he advocate another or different type of purity?
Ritual or cultic purity was paramount in Jewish society and life during the Second Temple period, and differences in purity halakhah were one of the factors that distinguished various movements. Therefore, considering purity is crucial in any attempt to interpret the historical Jesus within his contemporary context. In the latest or "third" phase of historical Jesus study, researchers have given prominence to Jesus' social and cultural context. In keeping with this goal, Thomas Kazen discusses the historical Jesus alongside what we know of Jewish purity halakhah of his time and explains Jesus' attitude toward impurity. Kazen balances the work of New Testament scholars on Judaism and legal matters by incorporating the historical Jesus studies of Jewish scholars, seeking to engage students of the historical Jesus with the primary materials relating to legal matters.