ISB ~ Romans 8 v3

the likeness of sinful flesh:Christ did not become a ’ sinner when he became man, but he did assume our mortal condition (Jn 1:14). This enabled him to die and, by this means, to defeat death and the devil for ever (Heb 2:14).

for sin:The Greek is identical to a shorthand expression used in the Greek version of Leviticus for a sacrificial sin-offering (Lev 4:24; 6:18; 14:19). If Paul had this in mind, as many hold, he is claiming that Jesus was sent by the Father to be an offering for sin. See note on 2 Cor 5:21.