Yahya related to me from Malik from Yahya ibn Muhammad ibn Talhafrom Uthman ibn Abd ar-Rahman that his father related to him that he had heard that Umar ibn al-Khattab used to wash what was beneath his waist wrapper with water.
Yahya said that Malik was asked what a man should do if, when he did wudu, he forgot and washed his face before he had rinsed his mouth, or washed his forearms before he had washed his face. He said, "If someone washes his face before rinsing his mouth, he should rinse his mouth and not wash his face again. If someone washes his forearms before his face, however, he should wash his forearms again so that he has washed them after his face. This is if he is still near the place (of wudu)."
Yahya said that Malik was asked about what a man should do if he had forgotten to rinse his mouth and nose until he had prayed, and he said, "He does not have to repeat the prayer, but should rinse his mouth and nose if he wishes to do any more prayers after that."

وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ يَحْيَى بْنِ مُحَمَّدِ بْنِ طَحْلاَءَ، عَنْ عُثْمَانَ بْنِ عَبْدِ الرَّحْمَنِ، أَنَّ أَبَاهُ، حَدَّثَهُ أَنَّهُ، سَمِعَ عُمَرَ بْنَ الْخَطَّابِ، يَتَوَضَّأُ بِالْمَاءِ لِمَا تَحْتَ إِزَارِهِ . قَالَ يَحْيَى سُئِلَ مَالِكٌ عَنْ رَجُلٍ تَوَضَّأَ فَنَسِيَ فَغَسَلَ وَجْهَهُ قَبْلَ أَنْ يَتَمَضْمَضَ أَوْ غَسَلَ ذِرَاعَيْهِ قَبْلَ أَنْ يَغْسِلَ وَجْهَهُ فَقَالَ أَمَّا الَّذِي غَسَلَ وَجْهَهُ قَبْلَ أَنْ يَتَمَضْمَضَ فَلْيُمَضْمِضْ وَلاَ يُعِدْ غَسْلَ وَجْهِهِ وَأَمَّا الَّذِي غَسَلَ ذِرَاعَيْهِ قَبْلَ وَجْهِهِ فَلْيَغْسِلْ وَجْهَهُ ثُمَّ لِيُعِدْ غَسْلَ ذِرَاعَيْهِ حَتَّى يَكُونَ غَسْلُهُمَا بَعْدَ وَجْهِهِ إِذَا كَانَ ذَلِكَ فِي مَكَانِهِ أَوْ بِحَضْرَةِ ذَلِكَ . قَالَ يَحْيَى وَسُئِلَ مَالِكٌ عَنْ رَجُلٍ نَسِيَ أَنْ يَتَمَضْمَضَ وَيَسْتَنْثِرَ حَتَّى صَلَّى قَالَ لَيْسَ عَلَيْهِ أَنْ يُعِيدَ صَلاَتَهُ وَلْيُمَضْمِضْ وَيَسْتَنْثِرْ مَا يَسْتَقْبِلُ إِنْ كَانَ يُرِيدُ أَنْ يُصَلِّيَ .