In Act 1, how do King Claudia and Queen Gertrude try to reason with Hamlet?

They use the reason that everybody dies and that, athough it is nice to mourne, Hamlet shouldn't be too sad.

Tis sweet and commendable in your nature, Hamlet, To give these mourning duties to your father. But you must know your father lost a father, That father lost, lost his, and the survivor bound In filial obligation for some term To do obsequious sorrow.