Ruth 4:5
Then said Boaz, What day thou buyest the field of the hand of Naomi, thou must buy it also of Ruth the Moabitess, the wife of the dead, to raise up the name of the dead upon his inheritance.
Cross-reference
In Ruth 3:12, Boaz reveals there is a nearer redeemer — this sets up the confrontation in Ruth 4:5 where Boaz addresses that relative.
In Ruth 3:13, Boaz promises to redeem if the nearer redeemer refuses — Ruth 4:5 shows him initiating that process.
In Genesis 38:8, Judah commands Onan to perform levirate marriage — the same custom Boaz invokes to perpetuate Elimelech's name.
In Deuteronomy 25:5, the levirate law is given — Ruth 4:5 applies this law to Ruth and the deceased husband.
In Deuteronomy 25:6, the purpose of levirate marriage is to perpetuate the dead's name — Ruth 4:5 echoes this exact phrase.
In Mark 12:19, the Sadducees quote the levirate law — a NT echo of the practice in Ruth 4:5.
In Luke 20:28, the Sadducees reference the same Mosaic law — parallel to the custom in Ruth 4:5.
In Matthew 22:24, the Sadducees cite the same levirate law — showing its continued relevance in NT debates.