Your Father, who sees what is done in secret, will reward you.
There is almost an implication to me here that our Father also sees the unrighteous acts we do in secret. The overall message in this passage in much more positive and inspirational, but my mind drifts towards the other side. Anyway, the Messiah powerfully advocates for humility here and it feels like a very comforting message to me. Perhaps it is because the way my mind works that I am almost seeing this loop that the righteous and wicked will both be rewarded. If you do right in secret or do wrong in secret, you get what you rightly deserve. If someone else wrongs you, even if it is in secret, even if you have no recourse, the Almighty sees it and He will give everyone their just deserts.