Authentic
graded by Salim al-Hilali
Muwatta Malik 399
وَحَدَّثَنِي عَنْ مَالِكٍ، أَنَّهُ بَلَغَهُ أَنَّ عَبْدَ اللَّهِ بْنَ مَسْعُودٍ، كَانَ يَدِبُّ رَاكِعًا .
Yahya related to me from Malik that he had heard that Abdullah ibn Masud used to move forward while in ruku.
Reported by Malik (No. 399).