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
abudawud:1963 – Muḥammad b. al-ʿAlāʾ > Ibn al-Mubārak > Yūnus > al-Zuhrī > Lammā Āttakhadh ʿUthmān al-Amwāl Bi-al-Ṭṭāʾif And ʾArād > Yuqīm Bihā Ṣallá Arbaʿ

When Uthman placed his property at at-Ta'if and intended to settle there, he prayed four rak'ahs. The rulers after him followed the same practice.  

أبو داود:١٩٦٣ – حَدَّثَنَا مُحَمَّدُ بْنُ الْعَلاَءِ أَخْبَرَنَا ابْنُ الْمُبَارَكِ عَنْ يُونُسَ عَنِ الزُّهْرِيِّ قَالَ

لَمَّا اتَّخَذَ عُثْمَانُ الأَمْوَالَ بِالطَّائِفِ وَأَرَادَ أَنْ يُقِيمَ بِهَا صَلَّى أَرْبَعًا قَالَ ثُمَّ أَخَذَ بِهِ الأَئِمَّةُ بَعْدَهُ