Ibn ‘Aqeel al-Hanbali (may Allah have mercy on him) said of himself:
It is not permissible for me to waste an hour of my life. When I stop discussing issues of knowledge and debating them (with others) and when I stop reading in a book, I would start pondering and thinking when I am resting and lying down, and before I get up, I will have already an idea that I should write down and I am very keen to increase my knowledge now I am in my eighties and more keen than when I was twenty years old.
[Quoted from him by Ibn al-Jawzi in al-Muntazam, 9/214]
Ibn al-Qayyim (may Allah have mercy on him) said:
A man’s time is in fact his life, and his eternal life, whether it is eternal bliss or eternal suffering, is based on how he spent it. Time is passing quickly; whatever time he spends for the sake of Allah and by the help of Allah, this is his true life; any other time is not counted as part of his life, even if he spends it doing what animals do. So if he spends his time in heedlessness, idle entertainment and false wishes, and the best of what he spends his time in is sleep and idleness, then his death is better than his life.
[Al-Jawaab al-Kaafi, p. 109]
via: Abu Emaan