The "Through New Eyes" commentary series is self-consciously, and at least in this volume, explicitly dependent upon the interpretive framework that James B. Jordan has helped advance. With this in mind--Lusk and Brito work hard to interpret the book of Ruth with a strong emphasis on biblical authority, interpretive maximalism--every word matters, leveraging biblical theology--connecting the book to the rest of Scripture, all through the lense that Jesus is the interpretive lens through which all Scripture must be understood.
One of the more important themes that the authors highlight is the command in Deuteronomy 23:2 that forbids anyone "born of a forbidden union" to enter the assembly of the Lord. The attentive reader will recall this and know that the line of Judah was a line born of a bastard (Perez--born of Judah and Tamar). This prevented anyone in the line of Judah from ruling as a king to the tenth generation. But in Ruth we see that this line is restored and the line of David preserved through the Moabite, Ruth, and David is the tenth generation.
This is instructive, because it again reminds us of the fact that Saul's kingship was a sort of Adamic seizing sin--seeking the forbidden fruit in an autonomous, high-handed way. Israel wanted a king at a time, and in a manner, that excluded the promised kingly seed of Judah.
Lusk and Brito do a great job explaining the kinsman-redeemer and levirate. I was surprised and persuaded by their reading of Ruth's midnight visitation of Boaz on the threshing floor. They argue that Ruth went there with the expectation that Boaz would sleep with her that very night, sealing the levirate marriage bond then and there. They argue this based upon Deuteronomy 25:25, which indicates the very act of consummation is the way the brother is to "take her as his wife." This interpretation does take most of the difficulties of Ruth 3 away.
There are several helpful appendices at the end, making the book longer, and doing some additional biblical and systematic theological work as well. I found this very helpful, and encourage others to read it as they study the book of Ruth.