Muwatta Malik 16
Mauquf Sahih Graded by Salim al-Hilali Book of The Times of Prayer · Hadith 16 of 1,858وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ نَافِعٍ، أَنَّ عَبْدَ اللَّهِ بْنَ عُمَرَ بْنِ الْخَطَّابِ، كَانَ يَقُولُ إِذَا فَاتَتْكَ الرَّكْعَةُ فَقَدْ فَاتَتْكَ السَّجْدَةُ .
Yahya related to me from Malik from Nafi that Abdullah ibn Umar ibn al-Khattab used to say, "If the ruku has passed you by, so has the sajda
References
Muwatta Malik 16
In-book: Book 1, Hadith 16 Source: hadith-api (fawazahmed0)