One of the numerous laws presented in Parashat Ki-Teitzei is the prohibition commonly known as shikhecha, which forbids one from returning to collect harvested sheaves of grain that were forgotten in the field. These forgotten bundles of grain must be left for the needy (24:19).
In defining the precise parameters of this command, the Mishna in Masekhet Pei’a (6:4) addresses the case of a person who begins collecting sheaves from the beginning of every row in the field. The Mishna establishes that the sheaves which were left on the ground after the farmer passed by them qualify as shikhecha, whereas the sheaves in front of him, which he did not yet pass by, may still be collected. Meaning, even if the farmer left a bundle of sheaves on the ground at the end of the row, and moved on to a different row, that bundle is not considered shikhecha, since he never passed by that area, and may very well still intend to go there and collect it. Bundles are considered shikhecha and thus left for the poor only after the farmer collecting the bundles passed by them without collecting them.
Rav Yehuda Leib Ginsburg, in his Mussar Ha-mishna, suggests explaining on the basis of this halakha the “Hadran” proclamation customarily made after completing the study of a masekhet (tractate of the Talmud). In this proclamation, we declare our intention to return to the masekhet, emphasizing that although we are now moving on to a different tractate, we are committed to returning to the recently-completed masekhet to review it and study it in greater depth. Rav Ginsburg explains that whenever we learn, we understand and accept the likelihood that we will forget a great deal of the material we study – despite Chazal’s stern warning in Pirkei Avot (3:8) about the gravity of forgetting Torah knowledge. The solution to this problem, Rav Ginsburg suggests, is found in this Mishna in Masekhet Pei’a. Since we sincerely and fully intend to return to the masekhet we just completed, the forgotten material is not considered “shikhecha” – truly “forgotten.” It resembles the bundles which the farmer had not yet passed, which, though temporarily neglected, cannot be said to have been actually “forgotten,” since the farmer still intends to pass by that area. By the same token, material that we have learned and then forgotten is not truly deemed “forgotten,” since we have plans to return to that area of study and review it. As long as this is our sincere intention, we are not considered to have actually “forgotten” material which we no longer remember.