Thus have I heard. Once the Venerable Mahaa-Kassapa and the Venerable Saariputta were staying near Benares, at Isipatana in the Deer Park. [Saariputta said:] "It is said, friend Kassapa, that without ardor and without taking care[1] one is unable to gain enlightenment, unable to gain Nibbaana, unable to gain relief from bondage,[2] but that with ardor, with taking care, enlightenment... can be gained. [How is this?]"
"When, friend, a monk thinks: 'Evil[3] and unskilled[4] states that have not arisen would, if they were to arise, be to my detriment,' and he does not arouse ardor; when he thinks: 'Evil and unskilled states that have arisen will, if they are not abandoned, be to my detriment,' and he does not arouse ardor; when he thinks: 'Skilled states that have not arisen, if they do not arise, this will be to my detriment,' and he does not arouse ardor; when he thinks: 'Skilled states that have arisen, if they should cease, this will be to my detriment,' and he does not arouse ardor — this, friend, is being without ardor."
[The same is repeated for 'without taking care']
"Thus it is friend, that without ardor, without taking care, one is unable to gain enlightenment, unable to gain Nibbaana, unable to gain relief from bondage. And how, friend, is one ardent? When a monk thinks: 'Evil and unskilled states...' ... 'Skilled states...' [As before but after each thought: 'and he arouses ardor'] — this, friend, is arousing ardor. [The same repeated with: 'taking care']. Thus it is, friend, that by arousing ardor and taking care one is able to gain enlightenment, to gain Nibbaana, to gain relief from bondage."