The word(s) "reinforce" appears 4 time(s) in 4 verse(s) in Quran in Saheeh International translation.

(1) [Remember] when you said to the believers, "Is it not sufficient for you that your Lord should reinforce you with three thousand angels sent down?

(سورة آل عمران, Aal-i-Imraan, Chapter #3, Verse #124)
(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) Yes, if you remain patient and conscious of Allah and the enemy come upon you [attacking] in rage, your Lord will reinforce you with five thousand angels having marks [of distinction]

(سورة آل عمران, Aal-i-Imraan, Chapter #3, Verse #125)
(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)

(3) [Remember] when you asked help of your Lord, and He answered you, "Indeed, I will reinforce you with a thousand from the angels, following one another."

(سورة الأنفال, Al-Anfaal, Chapter #8, Verse #9)
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(4) Then We gave back to you a return victory over them. And We reinforced you with wealth and sons and made you more numerous in manpower

(سورة الإسراء, Al-Israa, Chapter #17, Verse #6)
(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)