A Single Breath

The Buddha asked a Shramana [monastic], ‘How long is the human life span?’
He replied, ‘A few days.’
The Buddha said,‘You have not yet understood the way.’

He asked another Shramana, ‘How long is the human life span?’
The reply was, ‘The space of a meal.’
The Buddha said, ‘You have not yet understood the way.’

He asked another Shramana, ‘How long is the human life span?’
He replied, ‘The length of a single breath.’
The Buddha said, ‘Excellent. You have understood the way.’

- The Buddha
(Section 38 of ‘The Sutra in 42 Sections’)