Musnad Ahmad

It is narrated from Sayyiduna Ibn Amr (may Allah be pleased with him) that a man came to the service of the Noble Prophet (peace and blessings be upon him) and said, "O Messenger of Allah! Teach me the Qur'an." The Noble Prophet (peace and blessings be upon him) said to him: "Recite those three surahs which begin with 'Alif Lam Ra'." The man said, "I am old, my heart has become hard, and my tongue is heavy." The Noble Prophet (peace and blessings be upon him) said: "Then recite the three surahs which begin with 'Ha Meem'." He repeated his previous statement. The Noble Prophet (peace and blessings be upon him) advised him to recite the three surahs which begin with 'Sabbih', but he again repeated the same thing and said, "O Messenger of Allah! Teach me a comprehensive surah." The Noble Prophet (peace and blessings be upon him) taught him Surah Az-Zalzalah. When he finished reciting it, he said, "By Him Who sent you with the truth, I will never add anything to this," and he turned away and left. The Noble Prophet (peace and blessings be upon him) said about him twice: "This man has succeeded." Then the Noble Prophet (peace and blessings be upon him) said: "Bring him to me." When he came, the Noble Prophet (peace and blessings be upon him) said: "I have been commanded to offer sacrifice on the day of Eid al-Adha, and Allah has made this day a day of Eid for this Ummah." The man said, "Tell me, if I do not find any animal except the animal of my son, should I sacrifice that?" The Noble Prophet (peace and blessings be upon him) said: "No, rather trim your nails, cut your hair, shorten your mustache, and shave the hair below the navel. With Allah, these acts will be considered a complete sacrifice on your behalf."