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.
Qurʾān Bukhārī Muslim Nasāʾī Abū Dāwūd Tirmidhī Ibn Mājah Mālik Aḥmad Dārimī Ḥākim Ibn Ḥibbān Ṭabarānī Nasāʾī's Kubrá Bayhaqī al-Luʾluʾ wa-al-Marjān Ibn Rajab's Fifty Riyāḍ al-Ṣāliḥīn Aḥmad's Zuhd Suyūṭī
bayhaqi:2334 – Abū ʿAlī al-Rūdhbārī > Abū Bakr b. Dāsah > Abū Dāwud > Naṣr b. ʿAlī > Abū Aḥmad > al-ʿAlāʾ b. Ṣāliḥ > Zurʿah b. ʿAbd al-Raḥman > Ibn al-Zubayr

I heard Ibn al-Zubair say: Setting the feet right and placing one hand on the other is a sunnah. (Using translation from Abū Dāʾūd 754)   

البيهقي:٢٣٣٤ – وَأَخْبَرَنَا أَبُو عَلِيٍّ الرُّوذْبَارِيُّ أنبأ أَبُو بَكْرِ بْنُ دَاسَةَ ثنا أَبُو دَاوُدَ ثنا نَصْرُ بْنُ عَلِيٍّ ثنا أَبُو أَحْمَدَ عَنِ الْعَلَاءِ بْنِ صَالِحٍ عَنْ زُرْعَةَ بْنِ عَبْدِ الرَّحْمَنِ قَالَ

سَمِعْتُ ابْنَ الزُّبَيْرِ يَقُولُ صَفُّ الْقَدَمَيْنِ وَوَضْعُ الْيَدِ عَلَى الْيَدِ مِنَ السُّنَّةِ  

See similar narrations below:

Collected by Abū Dāwūd, Ṭabarānī
abudawud:754 – Naṣr b. ʿAlī > Abū Aḥmad > al-ʿAlāʾ b. Ṣāliḥ > Zurʿah b. ʿAbd al-Raḥman > Ibn al-Zubayr

I heard Ibn al-Zubair say: Setting the feet right and placing one hand on the other is a sunnah.  

أبو داود:٧٥٤ – حَدَّثَنَا نَصْرُ بْنُ عَلِيٍّ أَخْبَرَنَا أَبُو أَحْمَدَ عَنِ الْعَلاَءِ بْنِ صَالِحٍ عَنْ زُرْعَةَ بْنِ عَبْدِ الرَّحْمَنِ قَالَ

سَمِعْتُ ابْنَ الزُّبَيْرِ يَقُولُ صَفُّ الْقَدَمَيْنِ وَوَضْعُ الْيَدِ عَلَى الْيَدِ مِنَ السُّنَّةِ  

tabarani:13952 – ʿAbdullāh b. Aḥmad b. Ḥanbal > ʿAmr b. Muḥammad al-Nāqid > Abū Aḥmad al-Zubayrī > al-ʿAlāʾ b. Ṣāliḥ > Zurʿah b. ʿAbd al-Raḥman > ʿAbdullāh b. al-Zubayr

[Machine] I heard Abdullah bin Zubayr saying, "Straightening the feet and placing the hand upon the hand in prayer is from the Sunnah."  

الطبراني:١٣٩٥٢ – حَدَّثَنَا عَبْدُ اللهِ بْنُ أَحْمَدَ بْنِ حَنْبَلٍ قَالَ حَدَّثَنَا عَمْرُو بْنُ مُحَمَّدٍ النَّاقِدُ قَالَ حَدَّثَنَا أَبُو أَحْمَدَ الزُّبَيْرِيُّ قَالَ حَدَّثَنَا الْعَلَاءُ بْنُ صَالِحٍ قَالَ حَدَّثَنَا زُرْعَةُ بْنُ عَبْدِ الرَّحْمَنِ قَالَ

سَمِعْتُ عَبْدَ اللهِ بْنَ الزُّبَيْرِ يَقُولُ «صَفُّ الْقَدَمَيْنِ وَوَضْعُ الْيَدِ عَلَى الْيَدِ فِي الصَّلَاةِ مِنَ السُّنَّةِ»