Muwatta Malik 163
موطأ مالك#163Sahihوَحَدَّثَنِي عَنْ مَالِكٍ، عَنِ ابْنِ شِهَابٍ، عَنْ عَلِيِّ بْنِ حُسَيْنِ بْنِ عَلِيِّ بْنِ أَبِي طَالِبٍ، أَنَّهُ قَالَ كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم يُكَبِّرُ فِي الصَّلاَةِ كُلَّمَا خَفَضَ وَرَفَعَ فَلَمْ تَزَلْ تِلْكَ صَلاَتَهُ حَتَّى لَقِيَ اللَّهَ .
Yahya related to me from Malik from Ibn Shihab that AIi ibn Husayn ibn Ali ibn Abi Talib said, "The Messenger of Allah, may Allah bless him and grant him peace, used to say, 'Allah is greater' whenever he lowered himself and raised himself, and he continued to pray like that until he met Al lah
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
In-book reference: 3:18