Matthew 26:7

In this woman is prefigured the people of the Gentiles, who gave glory to God in Christ's passion; for she anointed His head, but the head of Christ is God, and ointment is the fruit of good works. But the disciples, anxious for the salvation of Israel, say that this ought to have been sold for the use of the poor; designating by a prophetic instinct the Jews, who lacked faith, by the name of the poor.

(in Luc. 7, 37.) It is possible therefore that they were different persons, and so all appearance of contradiction between the Evangelists is removed. Or it is possible that it was the same woman at two different times and two different stages of desert; first while yet a sinner, afterwards more advanced.

Another Evangelist (John 12:3.) instead of 'alabastrum' has 'nardum pisticam,' that is, genuine, unadulterated. For let no one think that she who anointed His head and she who anointed His feet were one and the same; for the latter washed His feet with her tears, and wiped them with her hair, and is plainly said to have been a harlot. But of this woman nothing of this kind is recorded, and indeed a harlot could not have at once been made deserving of the Lord's head.

(de Doctr. Christ. iii, 12.) But let not any suppose that the Lord's feet were by this woman bathed in ointment after the manner which the luxurious and debauched use. In all things of this nature, it is not the thing itself, but the mind of him who uses it, that is in fault. Whoso uses things after such sort as to pass the bounds observed by good men with whom he lives, either has some meaning in what he does, or is vicious. What then is vice in others, in a divine or prophetic person is a sign of some great thing. The good odour is the good report which one has gained by the works of a good life, and in following Christ's footsteps sheds a most precious odour on His feet.

(Hom. in Ev. xxxiii. 1.) Or, we may think that this is the same woman whom Luke calls a sinner, and John names Mary.