What does Matthew 26:8 mean?

A woman at a dinner party has done an extraordinary and extravagant thing. She has poured a bottle of extremely expensive oil over Jesus' head to anoint Him. John 12:1–11 seems to describe the same moment, making this woman Mary, sister of Martha and Lazarus. The oil was a full pound of nard ointment that she also poured over Jesus' feet and then wiped off with her hair. By any measure, this is an act of enormous honor and respect, as well as an act of great and intimate humility.

How do the disciples reclining at the table with Jesus react to this aromatic devotion from the woman? Matthew tells us they are indignant, not because of the woman's boldness but because of the cost of the oil. "Why this waste?" they say. John, if telling the same story, makes it clear that the primary objection comes from Judas Iscariot, the disciple who will soon betray Jesus (John 12:4–6).