Albert Barnes on Matthew 26:7

There came unto him a woman. This woman was Mary, the sister of Lazarus and Martha, Jn 12:3.

Having an alabaster box. The alabaster is a species of marble, distinguished for being light, and of a beautiful white colour, almost transparent. It was much used by the ancients for the purpose of preserving various kinds of ointment in.

Of very precious ointment. That is, of ointment of much value; that was rare, and difficult to be obtained. Mark (Mk 14:3) and John (Jn 12:3) say, that it was ointment of spikenard. In the original it is nard. It was procured from an herb growing in the Indies, chiefly obtained from the root--though sometimes also from the bark. It was liquid, so as easily to flow when the box or phial was open, and was distinguished particularly for an agreeable smell. See Song 1:12. The ancients were much in the habit of anointing or perfuming their bodies, and the nard was esteemed one of the most precious perfumes. John says there was a pound of this, (Jn 12:3.) The pound in use among them was the Roman, of twelve ounces, answering to our Troy weight. That there was a large quantity is farther evident from the fact that Judas says it might have been sold for three hundred pence, (forty dollars,) [or 9,] and that the house was filled with the odour of the ointment, (John.)

And poured it on his head. They were accustomed chiefly to anoint the head, or hair. John says (Jn 12:3) that she poured it on the feet of Jesus, and wiped them with her hair. There is, however, no contradiction. She probably poured it both on his head and his feet. Matthew and Mark having recorded the former, John, who wrote his gospel in part to record events omitted by them, relates that the ointment was also poured on the feet of the Saviour. To pour ointment on the head was common. To pour it on the feet was an act of distinguished humility and attachment to the Saviour, and therefore deserved to be particularly recorded.

As he sat at meat. That is, at supper. In the original, as he reclined at supper. The ancients did not sit at their meals, but reclined at length on couches. Mt 23:6. She came up, therefore, behind him, as he lay reclined at the table; and bending down over the couch, poured the ointment on his head and his feet; and probably kneeling at his feet, wiped them with her hair.

(t) "Then came" Jn 11:1,2, 12:3