In the dead of night on a secluded threshing floor, a dramatic encounter unfolds, highlighting a delicate balance of family duty, self-restraint, and deep concern for a destitute widow. Amidst the darkness, Boaz offers a calming invitation, urging Ruth to stay and sleep peacefully, an invitation meant to quiet her stormy and anxious soul [אגרת שמואל]. Having just learned that there is another closer relative who has the primary right to redeem her, Ruth feels a sudden wave of embarrassment and wishes to flee. However, Boaz insists that she remain until morning [אגרת שמואל]. His command serves a dual purpose. Physically, it protects her from the hazards of the night and the potential harm of reckless youths who might accost a woman wandering alone in the dark [רלב״ג]. Emotionally, it proves to her that he is not repulsed by her bold approach, ensuring she does not slip away in shame [אלשיך].
Beyond immediate physical and emotional protection, Boaz's instruction carries a profound prophetic weight. It serves as an unspoken promise about her future. This will be the very last night she spends without a roof over her head and without a husband. From the following morning onward, she is destined to find permanent rest, secure an inheritance, and become a settled homemaker [רש״י, תורה תמימה].
Looking toward the morning, Boaz lays out his calculated strategy regarding the closer relative. There are varying traditions regarding this individual. Some suggest his actual name is Tov [ביאור שטיינזלץ, רלב״ג]. Others propose that the act of redemption itself would be a good and positive outcome for Ruth because this relative is an honorable and important man [אבן עזרא], or that he would perform the duty willingly [אגרת שמואל]. Yet, Boaz understands the deeper dynamics at play. He recognizes that the first relative is not a particularly spiritual man and would likely fulfill the obligation out of social shame rather than genuine desire, in stark contrast to Boaz's own wholehearted willingness to marry her [אגרת שמואל]. Knowing that the other relative is primarily interested in acquiring family land, Boaz plans to condition the purchase of the field on the requirement to marry Ruth. This act, akin to a Levirate marriage, is designed to establish a legacy for her deceased husband and release her spiritual bond to him. Boaz anticipates that the relative will refuse these terms, thereby paving the way for Boaz himself to step in [אלשיך].
To seal his intentions, Boaz makes a solemn oath by God, serving two complementary purposes. Externally, the oath is meant to instill absolute confidence in Ruth. She naturally fears that he might just be brushing her off with empty, comforting words, so his vow proves the utmost seriousness of his commitment [רש״י, רלב״ג]. Internally, the oath acts as a vital weapon in a fierce personal struggle. The seclusion of an unmarried man and woman in the middle of the night naturally awakens temptation. To decisively subdue his own urges, Boaz quickly swears by God that he will not touch her that night, committing instead to take her only through permissible, lawful marriage [רש״י, תורה תמימה]. Ultimately, this single vow binds his entire plan together: it serves as a strict boundary for his own desires until he speaks with the other relative, and it acts as an unbreakable guarantee to Ruth that if the other man refuses, Boaz will undoubtedly redeem her himself [מלבי״ם].