ENOfficial
‘Ali b. al-Husain told in mursal form that God’s Messenger said the takbir in prayer as often as he got down1 and got up2 and that this continued to be his method in prayer till he met God. 1. i.e. for bowing or prostration. 2. i.e. after prostration. Malik transmitted it.
Source: sunnah.com
Other translations
Arabic
وَعَنْ عَلِيِّ بْنِ الْحُسَيْنِ مُرْسَلًا قَالَ: كَانَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يُكَبِّرُ فِي الصَّلَاة كلما خفض وَرفع فَلم تزل صلَاته حَتَّى لَقِي الله تَعَالَى. رَوَاهُ مَالك
sunnah.com