The Mishna (40a) taught that witnesses are questioned by the court by means of both ḥakirot (interrogations), and bedikot (examinations). There are seven specific questions under the category of ḥakirot that deal with basic questions of time and place and if a witness cannot answer any one of the questions of ḥakirot, his testimony will not be accepted. Regarding bedikot the Mishna teaches that the judges can ask whatever they want, and if the witnesses cannot answer questions of bedikot, their testimony still stands. A story is related that ben Zakkai once demanded information about the stems of figs.
The Gemara on today’s daf presents an attempt by Rami bar Ḥama to connect the figs to the trial itself (e.g. the man was accused of picking them on Shabbat or of using them as a murder weapon), but it concludes with the words of Rav Yosef who says that ben Zakkai held a unique position that bedikot questions were the equivalent of ḥakirot questions, which allowed him to ask penetrating questions that others would not have used.
Who is ben Zakkai?
The Gemara is reluctant to identify him with the great tanna, Rabban Yoḥanan ben Zakkai, since the story in the Mishna places him as a member of the Sanhedrin dealing with capital cases, while we have a tradition that of the 120 years of his life Rabban Yoḥanan ben Zakkai spent the first 40 as a businessman, the next 40 as a student and the final 40 as a teacher. Furthermore we know that the Sanhedrin moved from its location on the Temple Mount and ceased to try capital cases 40 years before the destruction (see Rosh HaShana 31b), yet Rabban Yoḥanan ben Zakkai was active as a teacher and leader of the Jewish community after the destruction of the Second Temple. The Gemara concludes that he must have presented his idea of asking questions of bedikot that include such detailed information while he was still a student and was called simply ben Zakkai.