2 verses have
truthful
in Edition Clear Qur'an by Talal Itani / Al-Ankaboot (The Spider)

29:3We have tested those before them. God will surely know the truthful, and He will surely know the liars.

29:29You approach men, and cut off the way, and commit lewdness in your gatherings.” But the only response from his people was to say, “Bring upon us God’s punishment, if you are truthful.”