A.T. Robertson Commentary Romans 8:36

"Even as it is written, For thy sake we are killed all the day long; We were accounted as sheep for the slaughter." — Romans 8:36 (ASV)

Even as it is written (καθως γεγραπτα). He quotes Ps 44:23.

We are killed (θανατουμεθα). Present passive indicative of θανατοω for which see on 7:4. Same idea of continuous martyrdom in 1 Corinthians 15:31.

As sheep for the slaughter (ως προβατα σφαγης). Objective genitive (σφαγης).