The Messenger of Allah ﷺ drank some milk and he did not rinse his mouth nor did he perform ablution, and he offered the prayer.  

أَنَّهُ سَمِعَ أَنَسَ بْنَ مَالِكٍ يَقُولُ إِنَّ رَسُولَ اللَّهِ ﷺ شَرِبَ لَبَنًا فَلَمْ يُمَضْمِضْ وَلَمْ يَتَوَضَّأْ وَصَلَّى قَالَ زَيْدٌ دَلَّنِي شُعْبَةُ عَلَى هَذَا الشَّيْخِ