Mishkat al-Masabih #776

Abu Sa'id al-Khudri said, “We used to estimate how long God’s Messenger stood at the noon and the afternoon prayer, and we estimated that he stood in the first two rak'as as long as it takes to recite A.L.M. Tanzil, i.e. as-Sajda* (A version has, “In every rak'a as long as it takes to recite thirty verses.” We estimated that he stood half that time in the last two rak'as; that he stood in the first two of the afternoon prayer as long as he did in the last two at noon; and in the last two of the afternoon prayer about half that time.” * Al-Qur'an; 32. This sura has thirty verses. Muslim transmitted it.