ISB ~ John 12 v3

pure nard:An imported spice from India.

anointed the feet:Matthew and Mark have her also anoint the “head” of Jesus (Mt 26:7; Mk 14:3).

the house was filled:The detail suggests John is testifying to what he himself smelled on the occasion.

It may be symbolic of what Jesus says explicitly in the Synoptic tradition:the spread of the fragrance throughout the house anticipates the news of this event spreading throughout the world (Mt 26:13; Mk 14:9).