The Prophet ﷺ and his companions reached Mecca in the morning of the 4th Dhul-Hijja reciting Talbiya (O Allah! We are obedient to your orders, we respond 4 to your call) . . . intending to perform Hajj. The Prophet ﷺ ordered his companions to assume the lhram for Umra instead of Hajj, excepting those who had Hadi (sacrifice) with them.  

قَدِمَ النَّبِيُّ ﷺ وَأَصْحَابُهُ لِصُبْحِ رَابِعَةٍ يُلَبُّونَ بِالْحَجِّ فَأَمَرَهُمْ أَنْ يَجْعَلُوهَا عُمْرَةً إِلاَّ مَنْ مَعَهُ الْهَدْىُ  

Messenger of Allah ﷺ came along with his Companions when four days had passed out of ten days (of Dhu'l-Hijja) and they were pronouncing Talbiya for Hajj, and he (the Holy Prophet) commanded them to change (this Ihram) into that of 'Umra.  

قَدِمَ النَّبِيُّ ﷺ وَأَصْحَابُهُ لأَرْبَعٍ خَلَوْنَ مِنَ الْعَشْرِ وَهُمْ يُلَبُّونَ بِالْحَجِّ فَأَمَرَهُمْ أَنْ يَجْعَلُوهَا عُمْرَةً  

"The Messenger of Allah and his Companions came on the morning of the fourth day (of Dhul-Hijjah), reciting the Talbiyah for Hajj, and the Messenger of commanded them to exit Ihram". (Using translation from Nasāʾī 2870)  

قَدِمَ رَسُولُ اللهِ ﷺ وَأَصْحَابُهُ لِصُبْحِ رَابِعَةٍ وَهُمْ يُلَبُّونَ بِالْحَجِّ «فَأَمَرَهُمْ رَسُولُ اللهِ ﷺ أَنْ يَحِلُّوا»