The word(s) "doubter" appears 5 time(s) in 5 verse(s) in Quran in Saheeh International translation.

(1) The truth is from your Lord, so never be among the doubters.

(سورة البقرة, Al-Baqara, Chapter #2, Verse #147)
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(2) The truth is from your Lord, so do not be among the doubters.

(سورة آل عمران, Aal-i-Imraan, Chapter #3, Verse #60)
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(3) [Say], "Then is it other than Allah I should seek as judge while it is He who has revealed to you the Book explained in detail?" And those to whom We [previously] gave the Scripture know that it is sent down from your Lord in truth, so never be among the doubters.

(سورة الأنعام, Al-An'aam, Chapter #6, Verse #114)
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(4) So if you are in doubt, [O Muhammad], about that which We have revealed to you, then ask those who have been reading the Scripture before you. The truth has certainly come to you from your Lord, so never be among the doubters.

(سورة يونس, Yunus, Chapter #10, Verse #94)
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(5) Preventer of good, aggressor, and doubter,

(سورة ق, Qaaf, Chapter #50, Verse #25)
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