Isaiah
Isaiah 48:4ESV·traditional attribution

Because I know that you are obstinate, and your neck is an iron sinew and your forehead brass,

John Calvin Reformed @genevareformer

4. For I knew that thou art obstinate. Literally it is, “On account of my knowing,” or, “From nay knowing.” Here the Lord solemnly declares by the Prophet, that it was on account of the hard-heartedness of the people that he spake of future events; as if he had said that he acted more liberally towards them than he ought to have done.

Matthew Henry Presbyterian @wholebiblehenry

We may observe here, I. The hypocritical profession which many of the Jews made of religion and relation to God. To those who made such a profession the prophet is here ordered to address himself, for their conviction and humiliation, that they might own God's justice in what he had brought upon them. Now observe here, 1.

Commenting on Isaiah 48:1-8

John Gill Reformed Baptist @doctorgill

Because I knew that thou art obstinate,.... Or "hard" (a), hard hearted, an obdurate and rebellious people, contradicting and gainsaying: and thy neck is as an iron sinew; stiffnecked, inflexible, not compliant with the will of God, and his commands; unwilling to admit his yoke, and bear it: and thy brow brass; impudent, not ashamed of sin, nor blushing at it, refusing to receive correction...