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."
أَنَّ عَبْدَ اللَّهِ بْنَ عُمَرَ بْنِ الْخَطَّابِ كَانَ يَقُولُ إِذَا فَاتَتْكَ الرَّكْعَةُ فَقَدْ فَاتَتْكَ السَّجْدَةُ