en_tn/isa/48/03.md

Yahweh continues speaking to the people of Israel.

from my mouth they came forth

AT: "I spoke these things" (See: rc://en/ta/man/translate/figs-synecdoche)

your neck muscles tight as iron, and your forehead like bronze

"you have stiff necks and hard heads." Both of these phrases mean the people were stubborn. (See: rc://en/ta/man/translate/figs-simile and rc://en/ta/man/translate/figs-doublet)

I declared these things to you beforehand; before they happened I informed you

This is also saying the same thing twice for emphasis. (See: rc://en/ta/man/translate/figs-parallelism)