Behold, for peace I had great bitterness— That is to say, "When I thought of, perceived, and feared no evil, and seemed to enjoy my usual health, then this terrible evil came upon me: but thou hast delivered me, and freely forgiven me my sins." Thus Hezekiah does not claim exemption from guilt, but readily and humbly confesses that he deserved punishment, and was indebted solely to the divine mercy.
Related Commentaries of Isaiah 38:17
Isaiah 38:17
17 Behold, for peaced I had great bitterness: but thou hast in love to my soul delivered it from the pit of corruption: for thou hast cast all my sins behind thy back.