Did Friedrich Nietzsche say “And if thou gaze long into an abyss, the abyss will also gaze into thee”?

Did Friedrich Nietzsche say “And if thou gaze long into an abyss, the abyss will also gaze into thee”?

Found word for word. Yes. The text appears in works attributed to Friedrich Nietzsche. Source and location below.

146. He who fights with monsters should be careful lest he thereby become a monster. And if thou gaze long into an abyss, the abyss will also gaze into thee.
Beyond Good and Evil — Friedrich Nietzsche, CHAPTER IV. APOPHTHEGMS AND INTERLUDES · ¶165 · Public domain (US), Project Gutenberg #4363 · source

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