Passage
Thy first father hath sinned, and thy mediators have rebelled against me.
Thy first father hath sinned, and thy mediators have rebelled against me.
Isaiah 43:25 I, I [am] He that blotteth out thy transgressions for mine own sake, and I will not remember thy sins.
Isaiah 43:26 Put me in remembrance, let us plead together; rehearse thine own [cause], that thou mayest be justified.
Isaiah 43:27 Thy first father hath sinned, and thy mediators have rebelled against me.
Isaiah 43:28 And I have profaned the princes of the sanctuary, and have given Jacob to the ban, and Israel to reproaches.
The verse centers on "first", "father", "hath", "sinned", "mediators", "rebelled", and "against". It is saying that the verse draws attention to "first" and "father", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 26's "Put me in remembrance let us plead..." into verse 28's "And I have profaned the princes of...", so "first" and "father" belong inside that flow. In Isaiah context, the local focus is the Holy One of Israel, judgment and restoration, the servant of the LORD, and Zion's hope.
A plain takeaway is to answer the verse's own emphasis on "first" and "father" with trust shaped by these words, not by a vague optimism outside the passage.