Mary washed Jesus with her tears of repentance and her offering of sacrifice unto the Lord.  That oil and aroma that she poured with her tears is an aroma, pleasing unto the One that it is for.

“Then Mary took about a pint of pure nard, an expensive perfume; she poured it on Jesus' feet and wiped his feet with her hair. And the house was filled with the fragrance of the perfume.”
John 12:3