10296. '[And] pure frankincense' means truth on the inmost level, which is spiritual good. This is clear from the meaning of 'frankincense' as truth on the inmost level; and from the meaning of 'pure' as that which has been purged of the falsity of evil. The reason why truth on the inmost level, meant by 'frankincense', is spiritual good is that good with those who are in the Lord's spiritual kingdom is nothing other than truth. But this truth is called good when a person wills and does it from conscience and from affection. For in the case of those who are spiritual the entire will part of the mind has been corrupted; but the understanding part is preserved intact by the Lord, and within it the Lord implants a new will through regeneration. This new will is the conscience they have within them, which is a conscience composed of truth. All that is implanted in the understanding and emanates from the understanding is truth; for the human understanding is dedicated to the reception of truths belonging to faith, whereas the will is dedicated to receiving forms of good belonging to love. From all this it is evident that spiritual good is in its essence truth. As regards the new will in the case of those who are spiritual, that it is implanted in the understanding part of their minds, so that good with them is in its essence truth, see in the places referred to in 9277, 9596, 9684. Truth on the inmost level is called good because the more internal things are, the more perfect they are, and because the inmost part of a person is his will and what belongs to his will is called good. That 'frankincense' means truth on the inmost level, and so means spiritual good, may be recognized from the places quoted from the Word in 10177 above.
 Since spiritual good is meant by 'frankincense', and good is what reigns within all truths, arranges them into order, links them together, and imparts affection to them, frankincense is mentioned last; and the containers in which incense was burned were therefore called censers 1
. For the designation is derived from the essential element, which is good, even as for a like reason the term 'the anointing oil' was derived from the olive oil and not from the spices mixed into it when it was being prepared, that is to say, for the reason that 'the oil' meant good and 'the spices' different kinds of truth.
 The expression 'pure frankincense' is used because 'pure' means that which has been purged of the falsities of evil; and the word in the original language means inwardly pure, while another word is used to mean outwardly pure or clean. The fact that what is inwardly pure is meant by that word is clear in Isaiah,
Wash yourselves, render yourselves pure; remove the wickedness of your doings from before My eyes. Isaiah 1:16.
In vain have I rendered my heart pure, and washed my hands in innocence. Psalms 73:13.
'Rendering the heart pure' means being purified inwardly, and 'washing the hands in innocence ' being purified outwardly. In the same author,
By what will a young man render his way pure? By guarding himself according to Your Word. Psalms 119:9.
And in the same author,
... You may be pure in Your judging. Psalms 51:4.
For the other word that is used to mean outwardly pure or clean, see Leviticus 11:32; 12:7-8; 13:6, 13, 17, 23, 28, 34, 37, 58; 14:7-9, 20, 48, 53; 15:13, 28; 16:19, 30; 22:7; Jeremiah 13:27; Ezekiel 24:13; 39:12; and elsewhere.
1. Thuribula (censers) is derived from thus (frankincense).