ENOfficial
It was narrated that Abu Bushr said: "I heard Yusuf-meaning Ibn Mahak- narrating that Hakim said: 'I gave my pledge of allegiance to the Messenger of Allah (ﷺ), pledging that I would go down (in prostration) only after standing up from bowing.'"
Source: sunnah.com
Other translations
Arabic
أَخْبَرَنَا إِسْمَاعِيلُ بْنُ مَسْعُودٍ، قَالَ حَدَّثَنَا خَالِدٌ، عَنْ شُعْبَةَ، عَنْ أَبِي بِشْرٍ، قَالَ سَمِعْتُ يُوسُفَ، - وَهُوَ ابْنُ مَاهِكٍ - يُحَدِّثُ عَنْ حَكِيمٍ، قَالَ بَايَعْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم أَنْ لاَ أَخِرَّ إِلاَّ قَائِمًا .
sunnah.com