Every human being has a maximum duration of life of one hundred years, but for one who cannot control his senses, half of those years are completely lost because at night he sleeps twelve hours, being covered by ignorance. Therefore such a person has a lifetime of only fifty years.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
पुंसो वर्षशतं ह्यायुस्तदर्धं चाजितात्मनः । निष्फलं यदसौ रात्र्यां शेतेऽन्धं प्रापितस्तमः
puṃso varṣaśataṃ hyāyustadardhaṃ cājitātmanaḥ | niṣphalaṃ yadasau rātryāṃ śete'ndhaṃ prāpitastamaḥ
SB 7.6.6