The Messenger of Allah ﷺ entered the mosque and saw a rope stretched between two pillars.He asked, "What is this rope?"They said, "It belongs to Zaynab. She prays holding onto it, and when she grows weary, she clings to it."He said, "Untie it, untie it. Let one of you pray as long as he is energetic, and when he tires, let him sit down."
حدثنا عمران بن موسى الليثي حدثنا عبد الوارث بن سعيد عن عبد العزيز بن صهيب
أن رسول الله ﷺ دخل المسجد فرأى حبلا ممدودا بين ساريتين فقال ما هذا الحبل قالوا لزينب تصلي فيه فإذا فترت تعلقت به فقال حلوه حلوه ليصل أحدكم نشاطه فإذا فتر فليقعد
Bukhari recorded it in the Book of Tahajjud, chapter on what is disliked regarding overburdening oneself in worship, hadith no. 1150, and elsewhere, hadith no. 784, and Muslim recorded it in the Book of the Prayer of Travelers, chapter on the merit of consistent deeds such as night prayer and the like, through the hadith of Abdul-Warith with the same wording.