Alabaster is a sort of white marble, veined with various colors which is often hollowed out for boxes of ointment, because it keeps things of that nature most uncorrupt. Nard is an aromatic shrub of a large and thick root, but short, black and brittle; though unctuous, it smells like cypress, and has a sharp taste, and small and dense leaves. Its tops spread themselves out like ears of corn, therefore, its gift being double, perfumers make much of the spikes and the leaves of the nard. And this is what is meant by Mark, when he says “spikenard very precious”, that is, the ointment which Mary brought for the Lord was not made of the root of nard, but even, what made it more precious, by the addition of the spikes and the leaves, the gratefulness of its smell and virtue was augmented.
Theophylact, Matthew 26:2 : Or as is said in Greek, of pistic nard, that is, faithful, because the ointment of the nard was made faithfully and without counterfeit.
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).