Soncino on Yeshayahu 41:8
Having described the consternation and impotence of the idol-worshippers, the prophet, speaking in the Name of G-d, address Yisrael, G-d's servant, assuring him of Divine care and protection and announcing the crushing defeat of his enemies.
Yisrael - Yaakov, both names are synonymous for the entire nation.
Avraham My beloved - better, 'who loved Me.' He loved Me and clung to Me, and abandoned the idolators. So again in 2Divrei HaYamim 20:7.