What does John 12:5 mean?

One denarius was the typical daily wage of a laborer. Three hundred denarii was nearly a year's pay. Women, in that era, were not generally allowed to own property or land—and Lazarus' sister, Mary, has just poured perfumed oil worth about that much money on Jesus in an act of worship (John 12:1–3). This is a monumental sacrifice, probably representing her life savings, or something close to it. Thanks in part to the potent aroma, everyone in the building becomes aware of what has happened.

Judas, one of Jesus' disciples and His eventual betrayer (John 12:4), now pipes up to complain. According to other accounts, this criticism is echoed by others (Mark 14:3–11). On the surface, there is a certain logic to his response: do something useful, like helping the poor, rather than wasting resources on luxury. To be fair, many who nod along with Judas' criticism are doing so out of sincere concern.

This critique is actually a manipulative lie. Judas has no interest in the poor, but he knows how to disguise his real intentions. Judas is the disciples' treasurer, and the more money he controls, the more he can steal (John 12:6). Of course, this is not something the other disciples will learn until after Jesus has been arrested and Judas' lies are found out.