It is narrated from Sayyiduna Husayn bin Ali (may Allah be pleased with them both) that Sayyiduna Ali and Sayyiduna Hamzah (may Allah be pleased with them both) came to the Prophet (peace and blessings be upon him) after having taken a bath. The Prophet (peace and blessings be upon him) asked: "How did the two of you do it (regarding covering)?" One of them said: "O Messenger of Allah, I kept him covered with a cloth," and the other said the same. Then the Messenger of Allah (peace and blessings be upon him) said: "Had you done anything other than that, I myself would have covered you." This hadith has a sahih (authentic) chain of narration, but the two Shaykhs (Bukhari and Muslim) did not record it.