In the very first psalm of Tehillim we find a Torah scholar being compared to a tree. The blessed man who studies Torah day and night "shall be like a tree planted by streams of water that brings forth its fruit in its season and whose leaf shall not wither" (Tehillim 1:2-3)

King Davids analogy of the tree echoes in the words of his son Shlomo who declared that "where the tree falls there it shall lie" (Kohelet 11:3)

Farud was the town in which the Sage Bar Kafra lived until his passing. When Rabbi Yochanan visited there he asked if anyone recalled what Bar Kafra had ruled in regard to the halachic status of wine stored by a non-Jew. When a local scholar named Rabbi Tanchum quoted the liberal ruling of Bar Kafra, Rabbi Yochanan was deeply impressed with the fact that the sages teaching had been so absorbed by his townspeople. "The tree falls", he explained, refers to the passing of the Torah scholar, so that we cannot interpret "there it shall lie" as relating to his continued presence. We must therefore conclude that even when the Torah tree falls the fruits which have earlier fallen from it the Torah he taught to others in his community will remain as they did in the case of Bar Kafra.

We thus have two analogies relating to two different stages of the Torah scholars impact on others. The first is during his lifetime when he reaches the level that he is capable of teaching others. Back in the first perek of the mesechta (19b) the Sage Rava said of him that if he "brings forth his fruit in its season" he teaches Torah when he is capable of doing so then "his leaf shall not wither" he will meet with success and earn the blessings of Heaven.

The analogy in our gemara deals with the impact of that teaching which survives even after he is gone. The fruits which fell from the tree during its lifetime the teaching absorbed by his disciples will still remain.

Daniel, whose wisdom and heroism fill an entire sefer in Ketuvim (The Holy Writings) is best known for its miraculous survival in a den of hungry lions into which he had been cast by the Persian king for defying his ban on praying to G-d.

The Book of Daniel begins, however, with another example of his heroism in the service of G-d. Taken into Babylonian captivity along with the king and members of the royal family, Daniel was chosen to be trained as an attendant in the palace of Nevuchadenetzer. During this three-year course he was served with the nourishing food supplied by the palace kitchen.

"But Daniel determined in his heart that he would not defile himself with the patbag of the king nor with the wine of his drinkings" (Daniel 1:8). He found favor in the eyes of the officer in charge who replaced these items with a vegetarian diet and water.

What exactly did Daniel refrain from?

Wine is explicitly mentioned and the plural term "drinkings" is interpreted by our Sages as a reference to a second liquid oil. Daniel abstained from both of these in order to avoid the social contact arising from shared meals which might lead to intermarriage. Whether he adopted this only as a personal discipline or instituted, in his capacity as a leader of his people, a partial ban on such items for all Jews is a subject of debate in our gemara between the Sages Rav and Shmuel.

But what is meant by the patbag mentioned in the above passage?

The word pat is Hebrew for bread, and it would seem that Daniel abstained from the palace bread as well. Rashbam, quoted by Tosefot, states that it is improbable that Daniel and the comrades who joined him in this heroic adventure managed to retain their healthy condition without eating bread along with their vegetarian diet. His conclusion is that patbag is a reference to some royal delicacy which they rejected either for reasons of kashrut or separation.