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

(21) And if his shirt is torn from behind, then she hath lied and he is of the truthful.

(22) (And when he came to Joseph in the prison, he exclaimed): Joseph! O thou truthful one! Expound for us the seven fat kine which seven lean were eating and the seven green ears of corn and other (seven) dry, that I may return unto the people, so that they may know.

(23) He (the king) (then sent for those women and) said: What happened when ye asked an evil act of Joseph? They answered: Allah Blameless! We know no evil of him. Said the wife of the ruler: Now the truth is out. I asked of him an evil act, and he is surely of the truthful.

(24) Why bringest thou not angels unto us, if thou art of the truthful?

(25) And they say: When will this promise (be fulfilled), if ye are truthful?

(26) (Pharaoh) said: Produce it then, if thou art of the truthful!

(27) Thou art but a mortal like us. So bring some token if thou art of the truthful.

(28) Then make fragments of the heaven fall upon us, if thou art of the truthful.

(29) Is not He (best) Who produceth creation, then reproduceth it, and Who provideth for you from the heaven and the earth? Is there any Allah beside Allah? Say: Bring your proof, if ye are truthful!

(30) And they say: When (will) this promise (be fulfilled), if ye are truthful?