Adam Clarke on Isaiah 48:12

O Jacob "O Jacob, my servant" - After יעקב yaakob, a MS. of Kennicott's, two of De Rossi's, and the two old editions of 1486 and 1488, add the word עבדי abdi, "my servant," which is lost out of the present text; and there is a rasure in its place in another ancient MS. The Jerusalem Talmud has the same word.

I also am the last "I am the last" - For אף אני aph ani, "even I," two ancient MSS. and the ancient Versions, read ואני veani, "and I;" more properly.