The most beloved night has sleep built into it
Two reports, and the arithmetic in the first one is the thing to look at.
The night prayer described as the most beloved is the prayer of Dawud, and it is set inside a schedule: sleep half the night, pray a third of it, sleep a sixth of it. That is two thirds of the night asleep, in two separate sleeps, with the prayer in between.
And the second is the sentence this lesson could be built on by itself. Your body has a right over you, and your family has a right over you. It was said to a man who was praying all night and fasting every day, and the correction was not to try harder.
Qur’an and Sunnah
Narrated 'Abdullah bin 'Amr:Once Allah's Messenger (ﷺ) said to me, "I have been informed that you offer Salat (prayer) all the night and observe Saum (fast) during the day." I said, "(Yes) I do so." He said, "If you do so, your eye sight will become weak and you will become weak. No doubt, your body has right on you, and your family has right on you, so observe Saum (for some days) and do not observe it (for some days), offer Salat (for sometime) and then sleep
Sahih al-Bukhari 1153graded sound, sahihaynfull report
Narrated `Abdullah bin `Amr bin Al-`As:Allah's Messenger (ﷺ) told me, "The most beloved prayer to Allah is that of David and the most beloved fasts to Allah are those of David. He used to sleep for half of the night and then pray for one third of the night and again sleep for its sixth part and used to fast on alternate days
Sahih al-Bukhari 1131graded sound, sahihaynfull report