דברים, פרק כ״ד, פסוק כ״א

During the joyful agricultural harvest, a vineyard owner is obligated to remember the vulnerable members of society by leaving behind specific portions of the crop. As the farmer works through the vines gathering grapes, any produce inadvertently overlooked and left behind cannot be retrieved. The harvester is forbidden from turning back to collect these forgotten grapes; instead, they must remain in the vineyard as a gift for the impoverished [תורה תמימה, רלב״ג].

Beyond what is simply forgotten, there is a primary restriction against gathering undeveloped clusters. These are individual grapes that never fully ripened or formed into a complete, mature cluster, remaining small and scattered [ביאור יש"ר, ביאור שטיינזלץ]. Linguistically, the name for these defective formations is derived from the word for an infant, perfectly describing their small, stunted appearance compared to fully grown clusters. Additionally, the root concept implies an action performed at the end of a process, reflecting the typical practice of gathering these lesser remnants as the harvest concludes [מזרחי, מלבי״ם]. Because these underdeveloped formations are not guaranteed to grow in every vineyard—unlike standard tree fruits or grain—the instruction is conditional: if such clusters are encountered during the harvest, the owner must leave them [מזרחי].

The practical distinction between a standard cluster and an undeveloped one relies on the structure of the vine's central stem, which is conceptually compared to a human spine. A normal cluster, rightfully belonging to the owner, features a shoulder and a drop. The shoulder consists of smaller branches extending from the main stem, resting upon one another like a load carried on a person's shoulder. The drop refers to the dense, continuous line of grapes hanging at the very bottom of the stem. A cluster destined for the poor lacks both of these characteristics entirely, resulting in sparse and scattered grapes [רש״י, שפתי חכמים, חזקוני]. In cases where it is difficult to determine if the grapes are clustered closely enough to form a proper shoulder or drop, the uncertainty is resolved in favor of the poor, and the cluster is given to them [גור אריה].

There is a fundamental discussion regarding the exact scope of this obligation. One perspective argues that the requirement to leave these defective clusters only applies when the vineyard yields a substantial harvest of healthy grapes. If a vineyard produces exclusively poor-quality, undeveloped clusters, the owner is not expected to forfeit the entire season's crop. Another approach maintains that the restriction against gathering these clusters is absolute, regardless of the vineyard's overall yield. According to this view, the condition of harvesting merely dictates the specific time when the poor are permitted to enter the vineyard to collect their share—precisely as the harvest takes place [מלבי״ם].

In modern times, fulfilling this Commandment presents unique practical challenges. Economically, impoverished individuals rarely travel to fields to glean scattered grapes, which could lead to the fruit simply rotting away. However, the obligation can still be met through organized charity administrators who collect these agricultural gifts on behalf of those in need. Furthermore, contemporary mechanical harvesting introduces a technical complication, as machines blindly gather standard clusters and undeveloped ones together. This mixture creates a legal dilemma, because produce designated for the poor is exempt from standard agricultural tithes, whereas the regular harvest is fully obligated. The resolution to this issue is found during the winemaking process. Since tithes are only separated once the grapes have been crushed into liquid wine, the small amount of undeveloped juice becomes entirely nullified within the larger volume of the vat, seamlessly resolving the legal complication [ברכת אשר על התורה].