I heard the Messenger of Allah ﷺ, while he was at al-Aqiq, saying, "A messenger came to me tonight from my Lord and said, 'Pray in this blessed valley and say, an Umra combined with a Hajj.'"Walid said, meaning Dhul-Hulayfa.
حدثنا الوليد بن مسلم حدثنا الأوزاعي أن يحيى بن أبي كثير حدثه عن عكرمة مولى ابن عباس قال سمعت ابن عباس يقول سمعت
سمعت رسول الله ﷺ وهو بالعقيق يقول أتاني الليلة آت من ربي فقال صل في هذا الوادي المبارك وقل عمرة في حجة قال الوليد يعني ذا الحليفة
Its isnad is sahih. Aqiq here refers to the one in the bottom of the valley of Zulhulayfa, which is the nearest one to it, as Yaqut said in Mujam al-Buldan, and Walid bin Muslim likewise explained it this way here. Ibn Athir was mistaken in Nihayah when he took it to be the Aqiq that is in Madinah.