"Anas said: 'I heard the Prophet reciting the Talbiyah for 'Umrah and Hajj together. I told Ibn 'Umar about that and he said: "He recited the Talbiyah for Hajj only. I met Anas and told him what Ibn 'Umar had said, and Anas said: "do you think of us as no more than children? I heard the Messenger of Allah say: 'Labbaika 'Umratan wa Hajjan ma'an (Here I am (O allah) for 'Umrah and Hajj together) (sahih)
سَمِعْتُ النَّبِيَّ ﷺ يُلَبِّي بِالْعُمْرَةِ وَالْحَجِّ جَمِيعًا فَحَدَّثْتُ بِذَلِكَ ابْنَ عُمَرَ فَقَالَ لَبَّى بِالْحَجِّ وَحْدَهُ فَلَقِيتُ أَنَسًا فَحَدَّثْتُهُ بِقَوْلِ ابْنِ عُمَرَ فَقَالَ أَنَسٌ مَا تَعُدُّونَا إِلاَّ صِبْيَانًا سَمِعْتُ رَسُولَ اللَّهِ ﷺ يَقُولُ لَبَّيْكَ عُمْرَةً وَحَجًّا مَعًا