When Boaz raised the opportunity to marry Ruth and redeem Mahlon’s name, property, and future, the man who was the nearer-kinsman refused. In a matter of seconds, this un-named redeemer went from the “I will redeem” (Ruth 4:4) to “I cannot redeem” (Ruth 4:6).  

I. A Redeemer. The first mention of redemption in the Bible is in 6" class="scriptRef">Genesis 48:15-16, where the Angel of the Lord is called the redeemer. This Angel of the Lord is awesomely unique. He forgave sin (Ex 23:20-22; Is 43:25); possessed power to give life (Gen 16:10); was all-knowing (Gen 16:13; Ex 3:7); blessed God’s people (Gen 16:7-12; 48:16); and made and kept covenants (Judg 2:1). He is holy (Josh 5:13-15), accepted worship (Judg 6:18-21), and spoke as God (Gen 22:12). He is called the Judge of all the earth (Gen 18:25) and God (Gen 16:13; 32:30; Ex 3:2, 6; Judg 6:22-23; 13:21-22). He is none less than the pre-Incarnate Christ, and was intimately involved in human history before His physical incarnation.
The second mention is Exodus 6:6-7 where God declares Himself to the first redeemer of a politically enslaved Jewish nation. Israel couldn’t redeem itself, they needed one greater than Egypt and slavery. Likewise, sinful mankind needs One greater than sin, Satan, and this world’s system to free us (Eph 2:1-3; Jn 8:34-36).  

II. A Mediator (Ruth 4:7-8). The nearer-kinsman than Boaz feared what he would lose by redeeming Ruth and refused to marry Ruth. When Levirate marriage was rejected, the Law called for the widow to remove the man’s shoe and spit in his face (Deut 25:5-10). Without written records, this drama would be remembered by witnesses. The shoe likely represented walking over a piece of land to show ownership (Gen 12:17; Deut 1:36; Josh 1:3). Without Ruth present, Boaz became her mediator.
With the nearest kinsman refusing to marry Ruth, Boaz openly declared his purchase of the family’s property and his marriage to Ruth.
The Bible offers 4 purposes in God’s institution of marriage: (1) Bearing children, especially children raised in a godly home (Ps 127:3-5; Mal 2:15); (2) Cooperation in serving God (Gen 2:18); (3) Promoting sexual fidelity (1 Cor 7:2); (4) Symbolizing the relationship of Jesus for the Church (Eph 5:23-32).  

III. The Praise (Ruth 4:9-12). The redemption of Elimelech’s property and family brought praise for Boaz and Ruth from the witnesses. They prayed for: 

(A) Ruth’s Fruitfulness  like Jacob’s two wives (Gen 35:23-24).     
(B) Boaz’s Fruitfulness as a Bethlehemite (1 Sam 16:1-4; Lk 1-7).
(C) Boaz and Ruth’s House would be like Perez’s, God’s providential provision out of sin (Gen 38).

Ruth was accepted and included in the Jewish family and God’s blessing (Eph 1:11, 18; 2:11-13). She was no longer an outsider because Boaz gave out of his wealth to redeem.  
Scripture points us to Jesus, the perfect God and perfect Man. Ruth’s redemption reminds us of Christ Jesus’ loving work of redeeming the Church (Eph 2:11-13). By His death and resurrection, we are made His inheritance (Eph 1:11, 18) and receive an inheritance in Him (Eph 1:3). He gave more than out of His wealth, He gave Himself to save us (2 Cor 8:9; Jn 10:11-18), suffering to redeem God’s elect. Ruth was utterly blessed through Boaz, despite being an outsider and an outcast.
The Old Testament records the lives of a number of such outcast women. Tamar (Gen 38), Rahab (Josh 2:1), Ruth (Ruth 1:4), and Bathsheba (2 Sam 11:4-5). All were sinners, whose redemption points us to Jesus, our Redeemer (Mt 1:3, 5-6).