9143. 'When fire breaks out' means anger arising from an affection for evil. This is clear from the meaning of 'fire' as love, at this point the love of evil and an affection for it, dealt with just above in 9141. The term 'affection for evil' is used because an extension from love is meant by an affection. The reason why 'fire' means anger arising from an affection for evil is that anger has its origin in that affection. For when that which a person loves is attacked fiery passion erupts and so to speak burns in him. This is the reason why anger is described in the Word as 'fire' and is said to be 'burning', as in David,

Smoke went up out of His nose, and fire out of His mouth; glowing coals flamed forth from Him. Psalms 18:8.

In the same author,

Kiss the Son lest He be angry, for His anger will shortly blaze up. Psalms 2:12.

In Isaiah,

Who among us will dwell with the devouring fire? Who among us will dwell with the hearths of eternity? Isaiah 33:14.

In the same prophet,

He poured out on him the wrath of His anger; He set him on fire round about, and he made no acknowledgement; He burned him, and yet he did not take it to heart. Isaiah 42:25.

In the same prophet,

Behold, Jehovah will come in fire, and His chariots will be like a whirlwind, to requite in the wrath of His anger; and His rebuke [will come] in flames of fire. Isaiah 66:15.

In Moses,

I looked back and came down from the mountain, when the mountain was burning with fire. I was extremely afraid on account of the anger and wrath with which Jehovah was angry with you. ¹ Deuteronomy 9:15, 19.

In these and many other places 'fire' is used to describe anger. And 'anger' is attributed to Jehovah, that is, to the Lord; but in fact it resides with man, 5798, 6997, 8284, 8483. The Lord appeared on Mount Sinai to the Israelite people in a way suited to the kind of people they were, therefore in fire, smoke, and thick darkness, see 6832. But it should be remembered that anger is fire bursting out from an affection for evil, whereas zeal is fire bursting out from an affection for good, 4164, 4444, 8598. Therefore 'fire' is also used to describe zeal, in Moses,

Jehovah your God is a devouring fire, a zealous ² God. Deuteronomy 4:24.

And in Zephaniah,

I will pour out onto them all the wrath of My anger, because in the fire of My zeal the whole earth will be destroyed. Zephaniah 3:8.

'The zeal of Jehovah' is love and mercy, but it is called anger because it is seen by the evil as anger when they incur the punishment of their evil, 8875.

Footnotes:

Like so many common verbs, the meaning of "know" in the Bible is varied and dependent on context. And in some cases -- when it is connected to ideas or objects -- its spiritual meaning and natural meaning are essentially the same. When the Bible talks about people knowing each other and especially when it talks about the Lord knowing people, the meaning has more to do with the states of love within people than it does with any factual knowledge. This makes sense if you think about it. When we really "know" somebody, what we mean is that we know what kind of person they are, what their motivations are, what they love, what they hate, what makes them tick. Those things are far more important than knowing their parents' names, where they were born or what year they graduated from school. Most often then, especially applied to people, "knowing" has to do with the perceptions we have about other people's loves and the conjunction that can exist between those with similar loves, not just a collection of facts.