Imam al-Shafi'i (may Allah have mercy on him) said concerning the hadith of Sayyiduna Ammar bin Yasir (may Allah be pleased with him): If Sayyiduna Ammar (may Allah be pleased with him) mentioned that their tayammum up to the shoulders in the presence of the Prophet (peace and blessings be upon him), when the verse was revealed, was by the command of the Prophet (peace and blessings be upon him), then it can only be that it is abrogated, since it is narrated that the Prophet (peace and blessings be upon him) "ordered tayammum of the face and the palms"; or else he narrated only one tayammum from him (peace and blessings be upon him).
(b) and his narration from him differed, so the narration of Ibn al-Simmah, which does not differ, is more established. Since it does not differ, it is more fitting to act upon it, because it agrees more with the Book of Allah than the two narrations that have been reported differently. Or else they heard the verse of tayammum when a prayer was due, so they performed tayammum and took precaution, going to the furthest extent to which the name "hand" applies, because that would not harm them, just as it would not harm them in ablution. When they came to ask the Prophet (peace and blessings be upon him), he (peace and blessings be upon him) informed them that less than what they had done would suffice them for tayammum. In my view this is the most fitting meaning of Ibn Shihab's narration of the hadith of Sayyiduna Ammar bin Yasir (may Allah be pleased with him), for the indications I have described.
(c) Imam al-Shafi'i (may Allah have mercy on him) said: What prevented us from taking the narration of Sayyiduna Ammar bin Yasir (may Allah be pleased with him) in which tayammum of the face and the palms is mentioned is the established report from the Messenger of Allah (peace and blessings be upon him) that he "wiped his face and his forearms", and that this is closer to the Qur'an and to analogy, since the substitute for a thing is like it.
(d) Imam al-Shafi'i (may Allah have mercy on him) narrated the hadith of Sayyiduna Ibn Umar (may Allah be pleased with him) that "one strike is for the face and another strike is for the hands up to the elbows".
(e) Imam al-Shafi'i (may Allah have mercy on him) said: I have seen our companions act upon this. Something has been narrated about it from the Prophet (peace and blessings be upon him); if I knew it to be established, I would not go beyond it nor have any doubt about it. Sayyiduna Ammar (may Allah be pleased with him) said that we wiped up to the shoulders in the presence of the Prophet (peace and blessings be upon him), and it is narrated from him, from the Prophet (peace and blessings be upon him), that "wiping is of the face and the palms".
(f) It is as though his saying, "We performed tayammum up to the shoulders in the presence of the Prophet (peace and blessings be upon him)," was not by his (peace and blessings be upon him) command. If the hadith of the Prophet (peace and blessings be upon him) mentioning wiping of the face and the palms is established from Sayyiduna Ammar bin Yasir (may Allah be pleased with him), and the narration up to the elbows is not established from the Prophet (peace and blessings be upon him), then acting on what is established from the Prophet (peace and blessings be upon him) is more fitting, and Sa'd bin Salim used to give fatwas according to this. It seems that in his early view he doubted whether both hadiths were established, for the reasons we have mentioned about each of them. The wiping of the face and the palms in the hadith of Sayyiduna Ammar (may Allah be pleased with him) is established, and it is more established than the narration of wiping the forearms, although the narration of the forearms is also good because of the corroborating reports we have mentioned, and it concerns another incident. If the narration of Ammar (may Allah be pleased with him) is about the beginning of tayammum, when the verse was revealed and they came to the Prophet (peace and blessings be upon him) and he (peace and blessings be upon him) told them that less than what they had done would suffice them for tayammum, then the narration of wiping the forearms came after it and is more worthy of being followed; it is closer to the Book and to analogy, and it is the practice of Sayyiduna Ibn Umar (may Allah be pleased with him), authentically reported from him. Wiping of the face and the palms has been narrated from Sayyiduna Ali and Sayyiduna Ibn Abbas (may Allah be pleased with them both), and the opposite has also been narrated from Sayyiduna Ali (may Allah be pleased with him).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 1014