Boaz has staked his claim on Naomi’s land and has shared his intention to marry Ruth, now he solidifies this by obtaining the elders’ consensus as witnesses and their blessing.
Ruth 4:11 (NET) All the people who were at the gate and the elders replied, “We are witnesses. May the Lord make the woman who is entering your home like Rachel and Leah, both of whom built up the house of Israel! May you prosper in Ephrathah and become famous in Bethlehem. 12 May your family become like the family of Perez – whom Tamar bore to Judah – through the descendants the Lord gives you by this young woman.”