8. Ṣalāh (Ritual Prayer)

٨۔ كتاب الصلاة

8.47 While entering the mosques etc. one should start with the right foot

٨۔٤٧ باب التَّيَمُّنِ فِي دُخُولِ الْمَسْجِدِ وَغَيْرِهِ

[Machine] And Ibn Umar would start with his right foot, and when he goes out, he would start with his left foot.

وَكَانَ ابْنُ عُمَرَ يَبْدَأُ بِرِجْلِهِ الْيُمْنَى، فَإِذَا خَرَجَ بَدَأَ بِرِجْلِهِ الْيُسْرَى.

bukhari:426Sulaymān b. Ḥarb > Shuʿbah > al-Ashʿath b. Sulaym from his father > Masrūq > ʿĀʾishah

The Prophet ﷺ used to start every thing from the right (for good things) whenever it was possible in all his affairs; for example: in washing, combing or wearing shoes.  

البخاري:٤٢٦حَدَّثَنَا سُلَيْمَانُ بْنُ حَرْبٍ قَالَ حَدَّثَنَا شُعْبَةُ عَنِ الأَشْعَثِ بْنِ سُلَيْمٍ عَنْ أَبِيهِ عَنْ مَسْرُوقٍ عَنْ عَائِشَةَ قَالَتْ

كَانَ النَّبِيُّ ﷺ يُحِبُّ التَّيَمُّنَ مَا اسْتَطَاعَ فِي شَأْنِهِ كُلِّهِ فِي طُهُورِهِ وَتَرَجُّلِهِ وَتَنَعُّلِهِ