en_tn/isa/06/13.md

it will again be destroyed

This can be stated in active form. Alternate translation: "armies will again destroy the land of Israel" (See: rc://en/ta/man/jit/figs-activepassive)

as a terebinth or an oak is cut down and whose trunk remains, the holy seed is in its stump

This simile means that even after Yahweh destroys Israel, he will still set apart people from among the Israelites to serve him. (See: rc://en/ta/man/jit/figs-simile)

terebinth

a kind of oak tree (See: rc://en/ta/man/jit/translate-unknown)

trunk ... stump

A trunk is the thick main stem of a tree. A stump is the part of a tree that remains in the ground after the tree is cut down.

the holy seed

The people who will serve Yahweh after armies destroy Israel are spoken of as if they were set apart as a holy seed. (See: rc://en/ta/man/jit/figs-metaphor)