I came to the Prophet ﷺ while he was at Muzdalifah and said, "Messenger of Allah, I have come to you from the mountains of Tayy. I have exhausted myself and worn out my mount. By Allah, I did not leave a single mountain without stopping at it. Is my Hajj valid?"He replied, "Whoever attends this prayer with us," meaning the dawn prayer at Muzdalifah, "and stands with us until we depart from it, having already stood at Arafat before that, by night or by day, his Hajj is complete and he has fulfilled its rites."
قال حدثنا هشيم عن ابن أبي خالد وزكريا عن الشعبي قال أخبرني
أتيت النبي ﷺ وهو بجمع فقلت يا رسول الله جئتك من جبلي طيء أتعبت نفسي وأنصبت راحلتي والله ما تركت من جبل إلا وقفت عليه فهل لي من حج فقال من شهد معنا هذه الصلاة يعني صلاة الفجر بجمع ووقف معنا حتى نفيض منه وقد أفاض قبل ذلك من عرفات ليلا أو نهارا فقد تم حجه وقضى تفثه
Its isnad is sahih, its narrators are well-known imams. Hushaym is Ibn Bashir, and Ibn Khalid is Ismail. Zakariya is Ibn Abu Zaida, and Shaybi is Amir bin Sharahil.The hadith was narrated by Abu Dawud, 2/196, no. 1949, in the book of rites, chapter on one who did not reach Arafah. And Tirmidhi, 3/237, no. 889, in the book of Hajj, chapter on what has been said about one who catches up with the imam. And Nasai, 5/264, no. 3043, in the book of rites, chapter on one who came to Arafah. And Ibn Majah, 2/1003, no. 3015, and Darimi, 2/83, no. 1888.