Nephi begins in this verse the description of the contrast between the states of the wicked and the righteous, again echoing the apocalyptic visions of Isaiah. The wicked will perish in suffering, and the righteous shall be spared. Nephi‘s unstated comparison is to the righteous remnant of Isaiah’s prophecies. His most likely reference is:
Isa. 10:16-23
16 Therefore shall the Lord, the Lord of hosts, send among his fat ones leanness; and under his glory he shall kindle a burning like the burning of a fire.
17 And the light of Israel shall be for a fire, and his Holy One for a flame: and it shall burn and devour his thorns and his briers in one day;
18 And shall consume the glory of his forest, and of his fruitful field, both soul and body: and they shall be as when a standardbearer fainteth.
19 And the rest of the trees of his forest shall be few, that a child may write them.
20 ¶ And it shall come to pass in that day, that the remnant of Israel, and such as are escaped of the house of Jacob, shall no more again stay upon him that smote them; but shall stay upon the LORD, the Holy One of Israel, in truth.
21 The remnant shall return, even the remnant of Jacob, unto the mighty God.
22 For though thy people Israel be as the sand of the sea, yet a remnant of them shall return: the consumption decreed shall overflow with righteousness.
23 For the Lord GOD of hosts shall make a consumption, even determined, in the midst of all the land.
The burnings are a cleansing of the wicked, and the righteous remnant will be spared. In both language and theme, Nephi is drawing upon this section of Isaiah.