Max cards in hand (magic the gathering)?

Question

"217.3b Each player has a maximum hand size, which is normally seven cards. A player may have any number of cards in his or her hand, but as part of his or her cleanup step, the player must discard excess cards down to the maximum hand size."

where do you discard cards? to your graveyard or into your libary

Answer 1

When you discard something, it goes into the graveyard.  If it were to go into your library somewhere, it would say "put ~ on the bottom or top of your library" or "shuffle ~ into your library"

Answer 2

Discarding something always means sending it to the graveyard.