Showing discards

[Drewbeezy09]

Sorry for another newb question. I know once cards are discarded players can't look through the discard decks. (Unless a card grants access to). I know there are instances were peeps will potentially see cards you may discard back but I can't find a rule that states a player(s) must show all discards before discarding. Let's say my turn comes and i have 5 cards. I kick open a door, battle a monster alone and win 2 treasure. I pull 2 cards (now holding 7 cards). I discard 2 cards to the treasure pile do I have to show both of em? Sorry I didn't find the ruling. Thanks for your reply(s).