Yahya related to me from Malik from Nafi from Abdullah ibn Umar that Umar ibn al-Khattab said, "No-one should leave the hajj until he has done tawaf of the House, and tawaf of the House is the final rite."
Malik said, commenting about Umar ibn al-Khattab's saying 'tawaf of the House is the final rite,' "In our opinion, and Allah knows best, that is because Allah, the Blessed and Exalted, says, 'Whoever exalts the rituals of Allah - that is from the taqwa of the hearts' (Sura 22 ayat 32), and He says, 'Then their halal place (of sacrifice) is at the Ancient House,' and the place of all the rituals and where they end is therefore at the Ancient House."

حَدَّثَنِي يَحْيَى، عَنْ مَالِكٍ، عَنْ نَافِعٍ، عَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ، أَنَّ عُمَرَ بْنَ الْخَطَّابِ، قَالَ لاَ يَصْدُرَنَّ أَحَدٌ مِنَ الْحَاجِّ حَتَّى يَطُوفَ بِالْبَيْتِ فَإِنَّ آخِرَ النُّسُكِ الطَّوَافُ بِالْبَيْتِ . قَالَ مَالِكٌ فِي قَوْلِ عُمَرَ بْنِ الْخَطَّابِ فَإِنَّ آخِرَ النُّسُكِ الطَّوَافُ بِالْبَيْتِ إِنَّ ذَلِكَ - فِيمَا نُرَى وَاللَّهُ أَعْلَمُ - لِقَوْلِ اللَّهِ تَبَارَكَ وَتَعَالَى {وَمَنْ يُعَظِّمْ شَعَائِرَ اللَّهِ فَإِنَّهَا مِنْ تَقْوَى الْقُلُوبِ} وَقَالَ {ثُمَّ مَحِلُّهَا إِلَى الْبَيْتِ الْعَتِيقِ} فَمَحِلُّ الشَّعَائِرِ كُلِّهَا وَانْقِضَاؤُهَا إِلَى الْبَيْتِ الْعَتِيقِ .