Charles Ellicott Commentary Isaiah 43:27

"Thy first father sinned, and thy teachers have transgressed against me." — Isaiah 43:27 (ASV)

Your first father has sinned ... —These words have been interpreted as referring to:

1. Adam
2. Abraham
3. Jacob
4. The ancestors of Israel collectively
5. One or another high priest individually

The third option, Jacob, fits best. (See Isaiah 43:28.)

Your teachers. —Literally, your interpreters (Job 33:23), or your mediators. The term is used in 2 Chronicles 32:31 of the ambassadors of the king of Babylon, and stands here for the priests and the prophets, who should officially have been the expounders of the Divine will.