Muwatta Malik · Hadith 396
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
Mauquf Sahih · Salim al-Hilali