Chandrakirti wrote in Engaging in the Middle Way (dBu-ma -la ‘jug-pa, Skt. Madhamakavatara) (III.6)
Because anger at bodhisattvas destroys the positive force from generosity and ethical discipline amassed over a hundred eons, there is no force more negative than that from a lack of patience.
Similarly, Shantideva wrote in Engaging in Bodhisattva Behavior (sPyod-‘jug, Skt. Bodhisattvacharyavatara) (V.1)
Whatever generosity, offerings to the Blissfully Gone (Buddhas) and the like, and positive deeds I've amassed over a thousand eon – one (moment of) hatred will destroy them all.
How to understand these statements?
If we get angry for even one moment at a bodhisattva whom we do not know is a bodhisattva, whether or not that person has the fault that we have become angry about, it destroys completely the positive potential that we have built up over 1000 eons to be benefited by him or her. Why is this so? Because everyone has been related in one way or another to everyone else over beginningless lifetimes, this bodhisattva and we have a karmic connection. Further, this bodhisattva has the karmic connection to benefit us because he or she has developed bodhichitta by wishing to benefit in all limited beings, and that includes us.
Each additional moment of our anger toward this bodhisattva destroys the positive potential built up for another 1000 eons. Our anger also severely weakens the rest of the positive potential we’ve built up to be benefited by him or her. That means we would need to purify ourselves of the negative potential from getting angry at this bodhisattva before we could be benefited by any positive action that we would direct toward him or her. This is what the assertion means that when a positive karmic potential is devastated – in other words, weakened – it will take longer to ripen and will ripen in a weaker form.
But if we know that this person is a bodhisattva, our one moment of anger at him or her destroys completely all our positive force we’ve built up over 1000 eons to be benefited by any bodhisattva and severely weakens the rest.
If we have had valid conceptual cognition of voidness and get angry at a bodhisattva whom we do not know is a bodhisattva, it just weakens, but does not destroy completely the positive potential we’ve built up over 1000 eons to be benefited by him or her. This is because we are able to meditate on ourselves, this bodhisattva and our anger as being like an illusion. Our anger also weakens the rest of our karmic potential to be benefited by that bodhisattva.
If we have had valid conceptual cognition of voidness and know that the person is a bodhisattva and we get angry with him or her, it weakens but does not destroy the positive potential we have built up over 1000 eons to be benefitted by any bodhisattva.
If we are a bodhisattva and we get angry for one moment at another bodhisattva on the same level as we are, whether or not we know this person is a bodhisattva, it destroys the positive potential we have built up over 100 eons to be benefited by any bodhisattva. If that bodhisattva we become angry with is on a higher or lower level than we are, the amount of positive potential destroyed will be proportionate.
In all these cases – whether or not we have valid conceptual cognition of voidness and whether or not we are a bodhisattva – if we get angry for even a moment at someone who is not a bodhisattva, our anger damages our positive potential to benefit from our interaction with this person. The damage, however, is much less than if we get angry at a bodhisattva.