Brass and iron as in Isaiah 48:4 and Daniel 7:19 signify what is hard.

In Genesis 4:22, brass signifies natural good. (Arcana Coelestia 421)

In Numbers 21:9, this signifies the Lord's divine natural. (Apocalypse Revealed 49)

Brass also signifies the good in man's natural and the sensuous in the Lord. (Arcana Coelestia 197, Apocalypse Revealed 49, Apocalypse Explained 705)

(Odkazy: Apocalypse Explained 70)

9918. 'Pomegranates' means factual knowledge of good. This is clear from the meaning of 'pomegranates' as factual knowledge of good, dealt with in 9552. The reason why pomegranates were placed on the hem of the robe was that 'the hem' meant the last and lowest or most external things of heaven and the Church, and the last or most external things there consist in factual knowledge, as is clear from what has been stated above, in 9915, 9917, about the order in which degrees of good and truth follow one another in heaven and with the individual human being. Factual knowledge of good and truth, which is meant by 'pomegranates', consists of matters of doctrine drawn from the Word; these matters of doctrine exist as factual knowledge to the extent that they are present in the memory which resides in the external or natural man. But when they pass into the memory which resides in the internal or spiritual man, which happens when a person's life is led in accord with them, the matters of doctrine that have to do with truth become matters of faith, and those that have to do with good become impulses of charity, and are called spiritual. When this happens they virtually disappear from the external or natural memory and seem to be as though instinctive, because they have been implanted in the person's life, just as anything through frequent practice becomes second nature. From all this it is evident what factual knowledge is and what use it serves, consequently what use matters of doctrine serve so long as they are retained merely as items of knowledge. For when they are retained merely as items of knowledge they occupy a position underneath intelligence and wisdom and do not rise up or pass into life until they become matters of faith and charity in the internal man.