The public gathering at the city gate marks the conclusion of the redemption process, carrying deep historical and spiritual weight. The crowd and the elders offer a blessing that links the new marriage to the ancient events that established the tribe of Judah, providing public support for a highly unusual union. The fact that everyone present spoke the exact same blessing in perfect unison indicates that their words were spoken with divine inspiration [אגרת שמואל].
By comparing the couple to the house of Perez, the elders specifically reference the family and tribe from which Boaz himself descends [רש״י, ביאור שטיינזלץ]. This historical parallel serves primarily to comfort Boaz. In redeeming Ruth, Boaz performs a variation of a Levirate marriage, stepping in as a relative rather than the brother of the deceased. The elders remind him that his ancestor Perez was also born from a complex Levirate situation, where Tamar conceived from her father-in-law Judah, an even more distant relative. Just as that unique union produced the glorious foundation of the house of Judah, the home built by Boaz and Ruth is destined for greatness [מלבי״ם, אגרת שמואל].
The comparison also serves to validate Ruth's unconventional behavior. Her bold midnight visit to the threshing floor could easily have been viewed as improper. By aligning her with Tamar, as well as the matriarchs Rachel and Leah, the people acknowledge that these women also took unusual and seemingly immodest initiatives. Because their intentions were pure and directed toward heaven, their actions were ultimately judged by their positive results. Ruth, driven by a sincere desire to attach herself to holiness, is therefore seen as acting in a worthy and desirable manner [אשכול הכופר, אגרת שמואל]. Adding a mystical dimension to this connection, Ruth is considered to be the actual reincarnation of Tamar, destined to bring forth a royal lineage [נחל אשכול].
It is precisely from these complicated beginnings, which carry superficial flaws like Ruth's Moabite ancestry or the incident between Tamar and Judah, that the royal house of David ultimately sprouts. God deliberately conceals the roots of the Messiah within these wondrous and unexpected events [אגרת שמואל, אשכול הכופר].
The blessing holds specific hopes for the couple's future children. The elders pray that only the first child born will be dedicated to preserving the name of Ruth's deceased first husband, while any subsequent children will belong entirely to Boaz's lineage [אגרת שמואל]. This future offspring also carries a hidden promise regarding the ultimate arrival of the King Messiah [אשכול הכופר]. Furthermore, the way the elders refer to Ruth highlights her unique status. Some understand their words as a testament to her righteousness, expressing the hope that all the children God grants Boaz will come exclusively from this righteous woman, and that his entire household will be built through her [תורה תמימה]. Alternatively, though Ruth was no longer young, the blessing served as a prayer for God to grant them children through a miracle, as if she were still in her youth [אשכול הכופר].