Mishkat al-Masabih 4 Prayer كتاب الصلاة 624

وَعَن أنس قَالَ: مَا كُنَّا نَشَاءُ أَنْ نَرَى رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فِي اللَّيْلِ مُصَلِّيًا إِلَّا رَأَيْنَاهُ وَلَا نَشَاءُ أَنْ نَرَاهُ نَائِما إِلَّا رَأَيْنَاهُ. رَوَاهُ النَّسَائِيّ

Anas said, “We never wanted to see God’s Messenger praying at night without doing so, and we never wanted to see him sleeping without doing so.”* *The tradition most probably means that he Prophet did not go to extremes in religious observances. Nasa’i transmitted it.