Sayyiduna Abu Sa'id Khudri (may Allah be pleased with him) narrates: We estimated the standing (qiyam) of the Prophet (peace and blessings be upon him) in the Zuhr and Asr prayers, so we estimated that in the Zuhr prayer, his standing was as long as it would take to recite thirty verses, that is, as long as Surah As-Sajdah. This estimation was for the first two rak'ahs, while in the last two rak'ahs it was half of that. Similarly, we estimated the standing of the Prophet (peace and blessings be upon him) in the first two rak'ahs of Asr, so it was as long as the last two rak'ahs of Zuhr, and we estimated his standing in the last two rak'ahs of Asr, so it was half of that. This narration is established and authentic.