It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that the Noble Prophet (peace and blessings be upon him) called the two prostrations of forgetfulness "al-Murghimatayn" (the two that disgrace and humiliate).
Hadith Referenceصحيح ابن خزيمه / جماع أبواب السهو فى الصلاة / 1063