The word(s) "unblest" appears 2 time(s) in 2 verse(s) in Quran in Abdullah Yusuf Ali translation.

(1) Praying: "O my Lord! infirm indeed are my bones, and the hair of my head doth glisten with grey: but never am I unblest, O my Lord, in my prayer to Thee!

(سورة مريم, Maryam, Chapter #19, Verse #4)
(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) "And I will turn away from you (all) and from those whom ye invoke besides Allah: I will call on my Lord: perhaps, by my prayer to my Lord, I shall be not unblest."

(سورة مريم, Maryam, Chapter #19, Verse #48)
(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)