Up early this morning working on a word study. As I dive deeper into the meaning of ἱλαστήριον [translated "propitiation"] in the context of Romans 3:25, it is interesting that Paul would chose a word that is referenced 27 times in the LXX, and in 21 of those instances it refers to as a place of propitiation ["the mercy seat"]. Here in Romans 3:25, he is using it as the means when ἱλασμός is used in the LXX as the means of propitiation ["sin offering" or "act of atonement"].
I believe Paul wanted to capture both the place and the means of atonement in this passage in Romans. While the work of the cross was certainly the means, the Jewish Christians in Rome would have been drawn to the image of the "mercy seat" which now has been replaced by the cross.
