Is it impermissible to discard in the trash papers that contain the names of the Messenger?

It is not permissible to dispose of papers containing the names of prophets in dirty or inappropriate places, because the sanctity is established for the letters and what is written. And whoever does so with the intention of mockery or insult has committed disbelief. The names of Allah and the names of the prophets are like the Mus'haf (Qur'an) in ruling due to their sanctity. However, for anything other than the Qur'an, a strong indication of insult is required.