The word(s) "truthful" appears 45 time(s) in 44 verse(s) in Quran in Muhammad Pickthal translation.

(1) And if ye are in doubt concerning that which We reveal unto Our slave (Muhammad), then produce a surah of the like thereof, and call your witness beside Allah if ye are truthful.

(2) And He taught Adam all the names, then showed them to the angels, saying: Inform Me of the names of these, if ye are truthful.

(3) Say (unto them): If the abode of the Hereafter in the providence of Allah is indeed for you alone and not for others of mankind (as ye pretend), then long for death (for ye must long for death) if ye are truthful.

(4) And they say: None entereth paradise unless he be a Jew or a Christian. These are their own desires. Say: Bring your proof (of what ye state) if ye are truthful.

(5) The steadfast, and the truthful, and the obedient, those who spend (and hoard not), those who pray for pardon in the watches of the night.

(6) All food was lawful unto the Children of Israel, save that which Israel forbade himself, (in days) before the Torah was revealed. Say: Produce the Torah and read it (unto us) if ye are truthful.

(7) Those who, while they sat at home, said of their brethren (who were fighting for the cause of Allah): If they had been guided by us they would not have been slain. Say (unto them, O Muhammad): Then avert death from yourselves if ye are truthful.

(8) (The same are) those who say: Lo! Allah hath charged us that we believe not in any messenger until he bring us an offering which fire (from heaven) shall devour. Say (unto them, O Muhammad): Messengers came unto you before me with miracles, and with that (very miracle) which ye describe. Why then did ye slay them? (Answer that) if ye are truthful!

(9) But as for those who believe and do good works We shall bring them into Gardens underneath which rivers flow, wherein they will abide for ever. It is a promise from Allah in truth; and who can be more truthful than Allah in utterance?

(10) Allah saith: This is a day in which their truthfulness profiteth the truthful, for theirs are Gardens underneath which rivers flow, wherein they are secure for ever, Allah taking pleasure in them and they in Him. That is the great triumph.