Muwatta Malik 47

وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ نَافِعٍ، أَنَّ عَبْدَ اللَّهِ بْنَ عُمَرَ، حَنَّطَ ابْنًا لِسَعِيدِ بْنِ زَيْدٍ وَحَمَلَهُ ثُمَّ دَخَلَ الْمَسْجِدَ فَصَلَّى وَلَمْ يَتَوَضَّأْ ‏.‏ قَالَ يَحْيَى وَسُئِلَ مَالِكٌ هَلْ فِي الْقَىْءِ وُضُوءٌ قَالَ لاَ وَلَكِنْ لِيَتَمَضْمَضْ مِنْ ذَلِكَ وَلْيَغْسِلْ فَاهُ وَلَيْسَ عَلَيْهِ وُضُوءٌ ‏.‏

Yahya related to me from Malik from Nafi that Abdullah ibn Umar prepared the body of one of Said ibn Zayd's sons for burial and carried it and then entered the mosque and prayed without doing wudu. Yahya said that Malik was asked whether it was necessary to do wudu because of regurgitating undigested food and he said, "No, wudu is not necessary, but the mouth should be rinsed

Reference

Muwatta Malik 47

In-book

Book 2, Hadith 16