We set out with the Messenger of Allah ﷺ as the crescent of Dhul-Hijjah was about to appear. The Messenger of Allah ﷺ said, "Whoever wishes to enter the state of ihram for Hajj, let him do so, and whoever wishes to enter the state of ihram for Umra, let him do so for Umra."
أخبرنا يحيى بن حبيب بن عربي عن حماد عن هشام عن أبيه
خرجنا مع رسول الله ﷺ موافين لهلال ذي الحجة فقال رسول الله ﷺ من شاء أن يهل بحج فليهل ومن شاء أن يهل بعمرة فليهل بعمرة
[Its chain of transmission is sahih]. Abu Dawud narrated it in the chapters on Hajj rites, under the chapter on performing Hajj alone, hadith no. 1778, from the hadith of Hammad bin Zayd, with this wording. It is also in al-Kubra, hadith no. 3698. It is agreed upon, narrated by Bukhari, hadith no. 317, and Muslim, hadith no. 115/1211, 117, from the hadith of Hisham bin Urwa, with this wording, at greater length.