Answer:
Gaze back into you
Step-by-step explanation:
The quote was by a German philosopher known as Friedrich Nietzsche.
He said ‘Whoever fights monsters should see to it that in the process he does not become a monster. And if you gaze long enough into an abyss, the abyss will gaze back into you’ .
The quote however means that we should be careful when dealing with something bad so we don’t become a part of it later on.