Thou shalt anoint Aaron and his sons - For the reason of this anointing, see Clarke's note on Exodus 29:7. It seems that this anointing oil was an emblem of Divine teaching, and especially of those influences by which the Church of Christ was, in the beginning, guided into all truth; as is evident from the allusion to it by St. John: "Ye have an unction from the Holy One, and ye know all things. The anointing which ye have received from him abideth in you, and ye need not that any man teach you; but as the same anointing teacheth you of all things, and is truth, and is no lie, and even as it hath taught you, ye shall abide in Him; 1 John 2:20, 1 John 2:27.
Compare Exodus 37:29.
Principal spices - i. e. the best spices.
Pure myrrh - Is a gum which comes from the stem of a low, thorny, ragged tree, that grows in Arabia Felix and Eastern Africa, called by botanists Balsamodendron myrrha. The word here rendered pure, is literally, “freely flowing”, an epithet which is explained by the fact that the best myrrh is said to exude spontaneously from the bark, while that of inferior quality oozes out in greater quantity from incisions made in the bark.
Five hundred shekels - Probably rather more than 15 1/4 lbs. See Exodus 38:24.
Cinnamon - is obtained from a tree allied to the laurel that grows in Ceylon (Sri Lanka) and other islands of the Indian Ocean, known in Botany as the Cinnamomum zeylanicum. It is the inner rind of the tree dried in the sun. It was imported from India in very early times by the people of Ophir, and brought with other spices from the south part of Arabia by the trading caravans that visited Egypt and Syria. The mention of these spices in Exodus may be taken as the earliest notice we have connected with commerce with the remote East.
Two hundred and fifty shekels - about 7 lbs. 14 oz.
Sweet calamus - The fragrant cane (or rush) was probably what is now known in India as the Lemon Grass.
Cassia - is the inner bark of an Indian tree (Cinnamomum cassia), which differs from that which produces cinnamon in the shape of its leaves and some other particulars. It was probably in ancient times, as it is at present, by far less costly than cinnamon, and it may have been on this account that it was used in double quantity.
An hin - Probably about six pints. See Leviticus 19:36.
An oil of holy ointment - Rather, a holy anointing oil.
After the art of the apothecary - According to Jewish tradition, the essences of the spices were first extracted, and then mixed with the oil. The preparation of the anointing oil, as well as of the incense, was entrusted to Bezaleel Exodus 37:29, and the care of preserving it to Eleazar, the son of Aaron Numbers 4:16. In a later age, it was prepared by the sons of the priests 1 Chronicles 9:30.
A stranger - See Exodus 29:33.
Cut off from his people - See Exodus 31:14.