‘ And he said, “Blessed be you of YHWH, my daughter. You have shown more kindness (love) in the latter end than at the beginning, inasmuch as you did not follow young men, whether poor or rich.”
Boaz was moved that such a presentable young woman should be willing to become his wife. It is apparent that he had to some extent fallen in love with her, for he felt only able to express his gratitude that she should have chosen him rather than a younger man, ‘whether rich or poor'. He for one clearly believed that she would have had good marriage prospects. Thus he blesses her in the Name of YHWH, for showing him even more kindness than she had before when she had gleaned in his fields and had spoken so graciously to him. He undoubtedly saw her being willing to marry him as a great kindness. It augured well for the future. Some see the ‘love -- at the beginning' as referring to the previous love shown to her former husband, a young man, and her mother-in-law, compare Ruth 2:11.