When those observing the vow
Of the active altruistic intention have trained well
In the three forms of discipline, their respect
For these three forms of discipline grows,
Which cause purity of body, speech and mind.
After taking the vow, which is aspirational bodhicitta, one engages in active bodhicitta. These are the two types of relative bodhicitta. Part of active bodhicitta is observing the moral conduct of body, speech, and mind. When this behavior becomes habitual, one has achieved purity of body, speech, and mind.