The word(s) "unknown" appears 2 time(s) in 2 verse(s) in Quran in Mohsin Khan translation.

(1) He said: "Verily! You are people unknown to me."

(سورة الحجر, Al-Hijr, Chapter #15, Verse #62)
(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) When they came in to him and said: "Salam, (peace be upon you)!" He answered: "Salam, (peace be upon you)," and said: "You are a people unknown to me."

(سورة الذاريات, Adh-Dhaariyat, Chapter #51, Verse #25)
(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)