I don't have specific info on a Week 8 matchup against the Commanders in the wiki. Based on what I do have, here's the latest on Saquon Barkley:
The most recent update (Oct 28) says Barkley returned in Week 7 from a hamstring injury, but back tightness limited him to just 9 snaps — though he was highly efficient (62 yards, 1 TD on 7 carries). He was cleared to play that Monday night game vs. Dallas.
As for this week vs. Washington — the wiki doesn't have a specific Week 8 injury report. The Eagles' page notes the team is in a complete tailspin (Hurts on IR, Lane Johnson retired, O-line in shambles), so Barkley's status would depend on how that back tightness responded during the week. You'd want to check the latest Friday injury report for his official designation.