At Bethany, what did Mary, Lazarus' sister, pour on Jesus' feet?

Answer: Expensive perfume

Mary took about a pint of expensive perfume made of pure nard, anointed Jesus' feet and wiped them with her hair.

“Then Mary took about a pint of expensive perfume, made of pure nard, and she anointed Jesus’ feet and wiped them with her hair. And the house was filled with the fragrance of the perfume.”— John 12:3 (BSB)