Yahya related to me from Malik that he had heard that Umar ibn al-Khattab and AIi ibn Abi Talib and Abu Hurayra were asked about a man who had intercourse with his wife while he was in ihram on hajj. They said, "The two of them should carry on and complete their hajj. Then they must do hajj again in another year, and sacrifice an animal."

Malik added that AIi ibn Abi Talib said, "When they then go into ihram for hajj in a future year they should keep apart until they have completed their hajj."

حَدَّثَنِي يَحْيَى، عَنْ مَالِكٍ، أَنَّهُ بَلَغَهُ أَنَّ عُمَرَ بْنَ الْخَطَّابِ، وَعَلِيَّ بْنَ أَبِي طَالِبٍ، وَأَبَا، هُرَيْرَةَ سُئِلُوا عَنْ رَجُلٍ، أَصَابَ أَهْلَهُ وَهُوَ مُحْرِمٌ بِالْحَجِّ فَقَالُوا يَنْفُذَانِ يَمْضِيَانِ لِوَجْهِهِمَا حَتَّى يَقْضِيَا حَجَّهُمَا ثُمَّ عَلَيْهِمَا حَجُّ قَابِلٍ وَالْهَدْىُ ‏.‏ قَالَ وَقَالَ عَلِيُّ بْنُ أَبِي طَالِبٍ وَإِذَا أَهَلاَّ بِالْحَجِّ مِنْ عَامٍ قَابِلٍ تَفَرَّقَا حَتَّى يَقْضِيَا حَجَّهُمَا ‏.‏
USC-MSA web (English) reference : Book 20, Hadith 160
Arabic reference : Book 20, Hadith 862