Many of Baha'u'llah's writings were thrown into river Tigris

When Baha'u'llah revealed this work (Lawh-i Huriyyih), he wanted it thrown in the Tigris river, where many of his writings were thrown because they were beyond what any person could understand. However, his amanuensis begged for the tablet to be saved and Baha'u'llah consented to this.

http://whoisbahaullah.com/wib/writings