Voluntary prayers are best at home

A man's best prayer is in his house, except the obligatory prayer.

Narrated by Zaid ibn Thabit

Pray, O people, in your houses, for the best prayer of a man is in his house, except the obligatory prayer.

Sahih al-Bukhari 731, Sahih Muslim 781

What this hadith teaches

The obligatory prayers are for the masjid; the sunnah prayers are best at home, where they are more sincere.

Reference and grade

Grade
Sahih: agreed upon by al-Bukhari and Muslim
Narrator
Zaid ibn Thabit

The hadith in Arabic نص الحديث

فَإِنَّ أَفْضَلَ الصَّلاَةِ صَلاَةُ الْمَرْءِ فِي بَيْتِهِ إِلاَّ الْمَكْتُوبَةَ

Arabic text of Sahih al-Bukhari 731, as given on sunnah.com.