ENOfficial
Jabir reported God’s Messenger as saying, “The most excellent prayer consists in long standing in prayer.” Muslim transmitted it.
Source: sunnah.com
Other translations
Arabic
وَعَنْ جَابِرٍ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «أَفْضَلُ الصَّلَاةِ طُولُ الْقُنُوتِ» . رَوَاهُ مُسلم
sunnah.com