I love John's version, which we hear today. Not only does Mary dry the Lord's drenched feet with her hair, the gesture filled the whole house with fragrance. Everyone benefitted from her unmeasured generosity, but only Jesus really seemed to appreciate it.
I noticed a number of contrasts in the story, especially as John tells it (specifying that Judas kept the common purse, and tended to pocket the contents):
generosity // greed
giving // taking
unmeasured // calculating
loving // observing
cherishing // accusing
In other words:
Kingdom of God // Reign of sin
Judas seems threatened by Mary's reckless generosity. Why else would he attempt to squelch such an outpouring? She has introduced an uncontrollable factor into everyone else's relationship with Jesus, setting the bar rather high. After witnessing this, no one else can just give a little, can measure out their response to Jesus. No one can "match" her gift with precision so as to claim or attain parity. There is no standard measure, no way to establish rank. And yet, clearly, not everyone at the banquet table felt moved to such generosity. Where did it come from?
What if Mary's generosity is above all a response to a prior outpouring of generous love on God's part, a response to the presence of the Kingdom of God "in your midst" (Lk 17:21)? Mary is like the widow in the Temple, giving "all that she had" Lk 21:4). She knows that "the one who tries to save his life will lose it, but the one who loses his life for me and for the Gospel will save it" (Mk 8:35), and she stakes everything on that. Her generosity reflects a confidence, a security in God's provident love. After witnessing (at least in John's telling) the return of her brother from the grave at Jesus's word, she lives in a world of abundance, the same world of abundant grace you and I are invited to inhabit.
We are about to witness, through the Liturgy, the unmeasured generosity of Jesus toward us. What steps can we take to let go of any habitual calculation with God so as to receive his gift as it is given: "full measure, pressed down, shaken together, running over" (Lk 6:38)?