Sunan an-Nasa'i 2933
It was narrated that Nafi said:
"Abdullah bin Umar went out and he came to Dhul-Hulaifah he entered Ihram for Umrah. Then he traveled a short distance. Then he was afraid that he might be prevented from reaching the House. He said: 'If I am prevented I will do what the Messenger of Allah did.' He said: 'By Allah, Hajj is jut like Umrah; I ask you to bear witness that I have resolved to do Hajj with my Umrah.' He traveled on until he reached Qudaid, where he bought a Hadi. Then he came to Makkah, and circumambulated the House seven times, and performed Sai between As-Safa and Al-Marwah and said: 'This is what I saw the Messenger of Allah doing.'"
أَخْبَرَنَا عَلِيُّ بْنُ مَيْمُونٍ الرَّقِّيُّ، قَالَ حَدَّثَنَا سُفْيَانُ، عَنْ أَيُّوبَ السَّخْتِيَانِيِّ، وَأَيُّوبَ بْنِ مُوسَى، وَإِسْمَاعِيلَ بْنِ أُمَيَّةَ، وَعُبَيْدِ اللَّهِ بْنِ عُمَرَ، عَنْ نَافِعٍ، قَالَ خَرَجَ عَبْدُ اللَّهِ بْنُ عُمَرَ فَلَمَّا أَتَى ذَا الْحُلَيْفَةِ أَهَلَّ بِالْعُمْرَةِ فَسَارَ قَلِيلاً فَخَشِيَ أَنْ يُصَدَّ عَنِ الْبَيْتِ فَقَالَ إِنْ صُدِدْتُ صَنَعْتُ كَمَا صَنَعَ رَسُولُ اللَّهِ صلى الله عليه وسلم قَالَ وَاللَّهِ مَا سَبِيلُ الْحَجِّ إِلاَّ سَبِيلُ الْعُمْرَةِ أُشْهِدُكُمْ أَنِّي قَدْ أَوْجَبْتُ مَعَ عُمْرَتِي حَجًّا ‏.‏ فَسَارَ حَتَّى أَتَى قُدَيْدًا فَاشْتَرَى مِنْهَا هَدْيًا ثُمَّ قَدِمَ مَكَّةَ فَطَافَ بِالْبَيْتِ سَبْعًا وَبَيْنَ الصَّفَا وَالْمَرْوَةِ وَقَالَ هَكَذَا رَأَيْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم فَعَلَ ‏.‏