Isaiah 43:27

Thy first father Undoubtedly Jacob, the eponymous hero of the nation, is meant (cf. Hosea 12:3 f.), not Abraham (who is never spoken of in the later literature as sinful), nor the earliest ancestors collectively; still less Adam.

thy teachers Lit. as R.V. thine interpreters (Genesis 42:23), and hence "mediators" (as Job 33:23; 2 Chronicles 32:31); used of the prophets only here. On the idea, see Jeremiah 23:11 ff. If the representative ancestor and the spiritual leaders of Israel were such, what must the mass of the nation have been!