Muwatta Malik:Burials:Hadith 545
وَحَدَّثَنِي عَنْ مَالِكٍ، أَنَّهُ سَأَلَ ابْنَ شِهَابٍ عَنِ الرَّجُلِ، يُدْرِكُ بَعْضَ التَّكْبِيرِ عَلَى الْجَنَازَةِ وَيَفُوتُهُ بَعْضُهُ فَقَالَ يَقْضِي مَا فَاتَهُ مِنْ ذَلِكَ ‏.‏

Yahya related to me that Malik asked Ibn Shihab about a man who caught some of the takbirs said over the corpse and missed the rest, and Ibn Shihab said, “He completes what he has missed.”