“Bhikkhus, do not reflect in an evil unwholesome way: ‘The world is eternal’ or ‘The world is not eternal’; or ‘The world is finite’ or ‘The world is infinite’; or ‘The soul and the body are the same’ or ‘The soul is one thing, the body is another’; or ‘The Tathagata exists after death,’ or ‘The Tathagata does not exist after death,’ or ‘The Tathagata both exists and does not exist after death,’ or ‘The Tathagata neither exists nor does not exist after death.’ For what reason? Because, bhikkhus, this reflection is unbeneficial, irrelevant to the fundamentals of the holy life, and does not lead to revulsion, to dispassion, to cessation, to peace, to direct knowledge, to enlightenment, to Nibbāna.
“When you reflect, bhikkhus, you should reflect: ‘This is suffering’; you should reflect: ‘This is the origin of suffering’; you should reflect: ‘This is the cessation of suffering’; you should reflect: ‘This is the way leading to the cessation of suffering.’ For what reason? Because, bhikkhus, this reflection is beneficial, relevant to the fundamentals of the holy life, and leads to revulsion, to dispassion, to cessation, to peace, to direct knowledge, sn.v.419 to enlightenment, to Nibbāna.
“Therefore, bhikkhus, an exertion should be made to understand: ‘This is suffering.’… An exertion should be made to understand: ‘This is the way leading to the cessation of suffering.’”