The word(s) "vigilant" appears 2 time(s) in 2 verse(s) in Quran in Muhammad Pickthal translation.

(1) And morning found him in the city, fearing, vigilant, when behold! he who had appealed to him the day before cried out to him for help. Moses said unto him: Lo! thou art indeed a mere hothead.

(سورة القصص, Al-Qasas, Chapter #28, Verse #18)
(Arabic, Transliteration, Urdu (Ahmed Ali), Urdu (Jalandhry), Farsi, Yusuf Ali, Shakir, Picthal, Mohsin Khan, French, Spanish, Indonesian, Malay, German, Bosnian, Russian, Dutch, Italian, Portuguese, Tafsir - Jalal ad-Din, Tafsir - King Fahad Quran Complex)

(2) So he escaped from thence, fearing, vigilant. He said: My Lord! Deliver me from the wrongdoing folk.

(سورة القصص, Al-Qasas, Chapter #28, Verse #21)
(Arabic, Transliteration, Urdu (Ahmed Ali), Urdu (Jalandhry), Farsi, Yusuf Ali, Shakir, Picthal, Mohsin Khan, French, Spanish, Indonesian, Malay, German, Bosnian, Russian, Dutch, Italian, Portuguese, Tafsir - Jalal ad-Din, Tafsir - King Fahad Quran Complex)