“Wa-lākinna al-birra man āmana bi-llāh”
“Rather, true piety belongs to the one who believes in God.” (al-Baqarah 2:177, excerpt)
“Al-birr” denotes righteousness, while “man āmana” refers to a believing person. The source elucidates the relation by construing an implied expression such as “the righteousness of one who believes.” This connects the abstract quality to its bearer.
The verse should not be treated as a flawed sentence. Arabic can rhetorically use a quality to characterize its possessor. Reconstruction serves understanding without requiring that one grammatical expansion be the only viable reading.
The emphasis falls on righteousness rooted in faith and its practical obligations, not merely on outward orientation.