How long wilt thou sleep, O sluggard? when wilt thou arise out of thy sleep? Proverbs 6:9
(ML 143.1)
Health is a great treasure. It is the richest possession mortals can have. Wealth, honor, or learning is dearly purchased if it be at the loss of the vigor of health. None of these attainments can secure happiness if health is wanting. It is a terrible sin to abuse the health that God has given us; for every abuse of health enfeebles us for life, and makes us losers.
(ML 143.2)
How prevalent is the habit of turning day into night and night into day. Many youth sleep soundly in the morning, when they should be up with the early singing birds, and be stirring when all nature is awake. Let youth practice regularity in the hours for going to bed and for rising, ... Let them purpose in their hearts that they will bring themselves under discipline, and practice orderly rules. God is a God of order, and it is the duty of the youth to observe strict rules, for such practices will work for their advantage.
(ML 143.3)
Since the work of building up the body takes place during the hours of rest, it is essential, especially in youth, that sleep should be regular and abundant.
(ML 143.4)
The majority of pleasure lovers attend the fashionable night gatherings, and spend in exciting amusements the hours God has given them for quiet rest and sleep in order to invigorate the body.... They are robbing the cheeks of the glow of health, and then to supply the deficiency use cosmetics.
(ML 143.5)
Would it not be better, therefore, to break up this habit of turning night into day, and the fresh hours of morning into night? If the youth would form habits of regularity and order, they would improve in health, in spirits, in memory, and in disposition.
(ML 143.6)