Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
tirmidhi:704Hannād > Wakīʿ > Hishām Binaḥwih Ilā > Qadr Qirāʾah Khamsīn Āyah

(Another chain) except that he said: "About the length for reciting fifty Ayahs."  

الترمذي:٧٠٤حَدَّثَنَا هَنَّادٌ حَدَّثَنَا وَكِيعٌ عَنْ هِشَامٍ بِنَحْوِهِ إِلاَّ أَنَّهُ قَالَ قَدْرُ قِرَاءَةِ خَمْسِينَ آيَةً قَالَ وَفِي الْبَابِ عَنْ حُذَيْفَةَ
Request/Fix translation

  

قَالَ أَبُو عِيسَى حَدِيثُ زَيْدِ بْنِ ثَابِتٍ حَدِيثٌ حَسَنٌ صَحِيحٌ وَبِهِ يَقُولُ الشَّافِعِيُّ وَأَحْمَدُ وَإِسْحَاقُ اسْتَحَبُّوا تَأْخِيرَ السُّحُورِ