I prayed four units with the Prophet ﷺ in Madinah and two units at Dhul-Hulayfah.
حدثنا سفيان قال سمعت إبراهيم بن ميسرة وحدثنا محمد بن المنكدر سمعتهما يقولان
صليت مع النبي ﷺ بالمدينة أربعا وبذي الحليفة ركعتين
Its isnad is sahih. Ibrahim bin Maysara was a precise, firmly reliable, trustworthy hadith master.The hadith was narrated by Bukhari 2/569, no. 1089 (Fath), in the chapter on shortening the prayer, shortening it when one leaves his place, and by Muslim 1/480, no. 690, in the book of travelers, the prayer of travelers and shortening it, and by Tirmidhi 2/431, no. 546, in the book of prayer, who graded it sahih, and by Darimi 1/424, no. 1508.