Exodus 30:34 - Matthew Poole's English Annotations on the Holy Bible

Stacte, and onycha, and galbanum: the Jews themselves are not agreed what these were, and it concerns not Christians much to know, the use of them being abolished. It is evident they were each of them sweet spices, and therefore this galbanum was not of the common kind, which gives a very ball scent. Of each shall there be a like weight, Heb. alone shall be with alone, i.e. each of these alone shall be with another alone, to wit, in equal quantity. Or it may note, that each of these was to be taken and beaten apart, and then mixed together. Or, it shall be alone alone, i.e. absolutely and certainly alone, the doubling of the word increasing the signification, and thus it doth not belong to all the ingredients, because the Hebrew verb is here of the singular number, but only to the frankincense; and the sense may be, that whereas the other things shall be tempered together, the frankincense should be alone, which may seem most agreeable both to the common use of frankincense, and to its differing nature from the other things mentioned, two of them at least being confessedly liquid things.