Kabbalah Amos 4:13: Sha'arei Kedusha & Sefer HaBahir

Our sages, of blessed memory, stated,⁵⁶³Talmud Bavli, Chullin 89a “The verse states,⁵⁶⁴Psalms 58:2 ‘Is there truly (HaUmnam-האמנם) silence (Eilem-אלם) when you should be speaking righteousness?’ That is, in what skill (Umanut-אמנות) should a person toil in this world? He should toil in making himself as if he is mute (Eelem-אלם).” Similarly, our sages, of blessed memory, stated,⁵⁶⁵Talmud Bavli, Chagigah 23a “When the Master would read the following verse, he would cry. The verse states,⁵⁶⁶Amos 4:13 ‘For behold, He Who forms the mountains and creates the wind, and declares to man what is his speech.’ This even includes the lighthearted and frivolous speech between a man and his wife before engaging in relations. Even if they are completely insignificant, they nevertheless written into a person’s ledger and read before him at the time of his death.”

And Rabbi Bun sat and expounded more, "Why is it written, '[God] forms light and creates darkness' (Isaiah 45:7)? [Since] there is substance in light, it is written, as ‘formation.’ [Since] there is not substance in darkness, it is written as ‘creation.’ As you say, '[God] forms mountains and creates wind' (Amos 4:13). And if you want, say, that light has existence in it, as it is written, 'And Elohim said, ‘Let there be light,’ and there is no existence except by making, [therefore] call it 'formation.' Darkness, since it does not involve making, only separation and setting aside, it is called ‘creation’ [בריאה], as it is said, 'So-and-so became healthy [הבריא].'"