Sahih Ibn Khuzaymah

Isa bin Hafs bin Asim says that my respected father, Hafs bin Asim (may Allah have mercy on him), narrated to me that I was on a journey with Sayyiduna Ibn Umar (may Allah be pleased with them both), and he performed two rak'ahs for the Zuhr and Asr prayers. Then he went towards his carpet or mat and saw some people offering voluntary (nafl) prayers. He asked, "What are these people doing?" I replied, "They are offering nafl prayers." He said, "If I had to offer (nafl) prayers before or after this (obligatory prayer), I would have completed the (obligatory) prayer itself. I remained in the company of the Messenger of Allah (peace and blessings be upon him) until his death, and he never offered more than two rak'ahs (in travel). And I also kept the company of Abu Bakr, Umar, and Uthman (may Allah be pleased with them), and they too performed (only the obligatory two rak'ahs) in this manner." These are the words of the hadith of Yahya bin Hakim. Imam Abu Bakr (may Allah have mercy on him) says that Sayyiduna Ibn Umar (may Allah be pleased with them both) used to prohibit offering nafl prayers after the obligatory prayer during travel and used to say, "If I had to offer nafl prayers, I would have completed the obligatory prayer." Therefore, how is it possible that he would have seen the Prophet (peace and blessings be upon him) offering two rak'ahs of sunnah after the obligatory Zuhr prayer during travel, and then prohibit someone who acts according to the action of the Prophet (peace and blessings be upon him)? Hazrat Salim and Hafs bin Asim (may Allah have mercy on him) are more knowledgeable and have better memory of the hadith of Sayyiduna Ibn Umar (may Allah be pleased with them both) than Atiyyah bin Sa'd (and their narrations are as follows, which are contrary to the narrations of Atiyyah).