Jamieson, Fausset and Brown on John 11:2

2. It was that Mary who anointed the Lord with ointment, &c.--This, though not recorded by our Evangelist till Joh 12:3, was so well known in the teaching of all the churches, according to our Lord's prediction (Mt 26:13), that it is here alluded to by anticipation, as the most natural way of identifying her; and she is first named, though the younger, as the more distinguished of the two. She "anointed THE Lord," says the Evangelist--led doubtless to the use of this term here, as he was about to exhibit Him illustriously as the Lord of Life.