The Prophet ﷺ said, "Umrah has been incorporated into Hajj until the Day of Resurrection."
حدثنا أحمد بن عبدة الضبي حدثنا زياد بن عبد الله عن يزيد بن أبي زياد عن مجاهد
عن النبي ﷺ قال دخلت العمرة في الحج إلى يوم القيامة
[Sahih] Ahmad narrated it (1/253) from the hadith of Yazid through the same route, and it has another route in Muslim, no. 1241, from Mujahid through the same route. There is also a narration on this subject from Suraqa bin Malik [Ahmad, 4/175] and Jabir bin Abdullah [Muslim, no. 1218].