"Seeing this, the disciples were indignant and said : What good is this loss ? Because this perfume could have been sold for a large sum and given to the poor. Jesus, knowing it, said to them : Why do you hurt this woman? She made a good [= beautiful, noble] work toward me." Matthew 26. 8-10
As the Passover was going to be celebrated in Jerusalem the following week, the city was overpopulated. It is in Bethany, not far from Jerusalem, "the city that kills the prophets" (Matt 23. 37), that Jesus goes out for the night with his disciples. That evening, he was served a supper in the house of Simon the leper. While Jesus is at table, Mary approaches him with an alabaster vase full of a perfume of great price; she breaks it and spreads the perfume on her head. The disciples, following Judas, express their indignation among themselves : "What good is this loss ?" They estimate this perfume to 300 deniers, the equivalent of a year's salary. They take back Mary severely. She has the wisdom to say nothing, but Jesus intervenes, knowing the motives that animate them : "Why do you hurt this woman ? She did a good work for me".
Mary had foreseen the coming death of her Master, while the disciples might compare the value of the perfume with the contents of the group's purse. They thought more of service than of master.
The pain that Marie felt was probably due less to the disciples' disdain for her than to their misunderstanding : they were utterly insensitive to this strong expression of love, respect and adoration for her Lord. His gesture, extravagant to the disciples' eyes, reflected the deep expression of his gratitude and appreciation for the infinite value of Jesus. For Mary, nothing was too expensive to honor Jesus. Judas estimated that 30 pieces of silver were enough to betray the Lord !
For Judas and the other disciples, this expense was a waste ; they did not look at the heart. And it's no different today in a world driven by the search for efficiency. But Jesus magnified the gesture of Mary : "Wherever this gospel will be preached, all over the world, we will also talk about what this woman has done in remembrance of her". And we remember his gesture again today.
Source (Pleasing the Lord)