A man reported,

I said to myself while traveling with the Messenger of Allah ﷺ, "By Allah, I will watch the Messenger of Allah ﷺ closely during his prayer to see exactly how he prays."After he prayed the night prayer, the Isha, he lay down for a portion of the night, then woke up and looked toward the horizon and said, "Our Lord, You have not created this in vain..." until he reached "...indeed, You do not break Your promise" [Al Imran 3:191–194].Then the Messenger of Allah ﷺ reached toward his bed and pulled out a tooth-stick, poured water from a vessel beside him into a cup, and cleaned his teeth. He then stood and prayed until I said to myself, "He has prayed for as long as he slept." Then he lay down again until I said, "He has slept for as long as he prayed." Then he woke up and did just as he had done the first time, and said the same as he had said before.The Messenger of Allah ﷺ did this three times before dawn.

عن رجل من أصحاب النبي ﷺ قال

قلت وأنا في سفر مع رسول الله ﷺ: والله لأرقبن رسول الله ﷺ الصلاة حتى أرى فعله، فلما صلى صلاة العشاء وهي العتمة اضطجع هويا من الليل، ثم استيقظ فنظر في الأفق فقال: {ربنا ما خلقت هذا بطلا} حتى بلغ: {إنك لا تخلف الميعاد} [سورة آل عمران: ١٩١-١٩٤] ثم أهوي رسول الله ﷺ إلى فراشه، فاستل منه سواكا، ثم أفرغ في قدح من إداوة عنده ماء، فاستن، ثم قام فصلى حتى قلت: قد صلى قدر ما نام، ثم اضطجع حتى قلت: قد نام قدر ما صلي، ثم استيقظ ففعل كما فعل أول مرة، وقال مثل ما قال: ففعل رسول الله ﷺ ثلاث مرات قبل الفجر.