en_tn_condensed/isa/02/21.md

the crevices in the rocks ... the clefts of the ragged rocks

If your language does not have two different words for "crevice" and "cleft," the space that appears between the two parts of a rock when it splits, you can combine these two phrases into one.

from the terror of Yahweh

because they are very afraid of Yahweh. See how you translated this in Isaiah 2:19.

the glory of his majesty

"the great beauty and power he has as king" or "his royal majesty." See how you translated this in Isaiah 2:10.

when he rises to terrify the earth

"when Yahweh takes action and causes the people of the earth to be terribly afraid of him." See how you translated this in Isaiah 2:19.