It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that once the Prophet (peace and blessings be upon him) performed ghusl (ritual bath) for janabah. When he came out after bathing, he saw that a small spot on his left shoulder had remained dry and water had not reached there. The Prophet (peace and blessings be upon him) took some dripping water from his hair and moistened that spot, and then went for prayer.