Or HaChaim on Exodus 30:23/אור החיים על שמות ל׳:כ״ג

1 ואתה קח לך, "And as for you, take for yourself, etc." The plain meaning of the verse is that Moses was to pay for the anointing oil out of his own pocket. This is why the Torah prefaced the directive with the word ואתה. Moses was to perform this particular commandment personally, as opposed to the other commandments concerning which G'd had also addressed him in direct speech, commanding him to perform the respective directive. Even though the Torah included the oil and the various spices in the list of items to be donated by the general public (25,3), the Torah here revealed its intention that these items be contributed by Moses personally.

2We have a Baraitha in Keritut 5 according to which Moses boiled the oil he took to anoint the priests with during the seven-day inaugural service of the Tabernacle. The remnants of the oil were preserved for future occasions. We have been taught that no such oil was ever again prepared at any time as the oil Moses had prepared was used again and again and it did not diminish in quantity. Maimonides rules in chapter in chapter 1 of his treatise Kley Hamishkan that apart from the quantity of anointing oil prepared by Moses, none was ever made again. This is the additional dimension of the words ואתה קח לך, indicating to Moses that only he would have the privilege to prepare this oil for anointing. Yalkut Shimoni item 764 sees in these words an allusion to the fact that in Messianic times it will be the resurrected Moses who will personally perform the Temple service. While it is true that the Torah also uses the expression: קח לך in connection with the fragrances for the frankincense in verse 34, the word ואתה does not appear in connection with that directive.

3וקנמן בשם מחציתו, "and half as much sweet cinnamon, etc." According to the Talmud in Keritut 5 this means that Moses was to bring five hundred units of sweet cinnamon but was to use only half of it in preparing the oil for anointing. The Talmud wonders if perhaps the directive in the Torah meant that Moses was only to bring two hundred and fifty units, i.e. "half," just like the amount of Kneh bossem mentioned immediately afterwards. The answer given is that if this had been the Torah's intention the directive should have read: קנמן בשם וקנה בשם מחצה, ומחצה חמישים ומתאים. Thus far the Talmud on the subject.

4Perhaps we can suggest an additional answer to the question raised by the Talmud. If the Torah had meant for Moses to contribute only a total of 250 units of sweet cinammon, the word "half of it," would have been totally superfluous; who does not know that 250 is half of 500? The Torah intended for two quantities of 250 units to be weighed [on opposite sides of the scale but that only one half was to be mixed in as an ingredient at that time. Ed.]

5I have seen a comment by Rabbi Avraham ibn Ezra who writes that it is not the custom of the Arabs to add even as much as the weight of a single grain of mustard to the recipe according to which they prepare such oils for incense. I do not think that this is correct. The process of weighing requires that one adds the quantities gradually in order to know when the correct weight has been achieved. I have seen that when the most experienced goldsmiths weigh gold they add another small weight to one side of the scales [and then presumably withdraw it, Ed.] in order to be certain that they have the correct weight. The reason that the Talmud did not mention our answer may be that according to the understanding of the Talmud the one unit of 250 remained separate at all times. The word מחציתו, "half of it," would then mean that Moses was to bring two amounts of 125 units each.