Luther's Allein
The qualifier alone (allein, in Luther’s (in)famous translation of Rom 3:28) is added to decouple these terms from other concepts with which they had become linked in Catholic thought and practice: faith from works; grace from merit; Christ from Mary (and the saints); scripture from the church’s magisterium. It does not supply the actual content of the terms.
David Fink, Divided by Faith: The Protestant Doctrine of Justification and the Confessionalization of Biblical Exegesis (Durham, NC: Duke University, 2012), 28