He is despised and rejected by men,A Man of sorrows and acquainted with grief.And we hid, as it were, our faces from Him;He was despised, and we did not esteem Him.
Surely He has borne our griefsAnd carried our sorrows;Yet we esteemed Him stricken,Smitten by God, and afflicted.
But He was wounded for our transgressions,He was bruised for our iniquities;The chastisement for our peace was upon Him,And by His stripes we are healed.
"Surely He hath" the tense is important here - so even though the prophet Isaiah is speaking about the future he still says "surely He hath." Now that means it's always been done! Your healing has been prepared for you! God sees you healed!