Rishi’s observation is quite right.
Without a past kamma (a kamma beeja) no good or bad thing can happen.
But the key point is that certain conditions must be satisfied for those kamma beeja to bring vipaka.
In particular, for a rebirth to occur at the cuti-patisandhi moment, “upadana paccaya bhava” must be satisfied. When one attains the Arahanthood, both avijja and tanha are completely removed and thus there will be no upadana for any kind of bhava in the 31 realms.
– Therefore, while there may be many kamma beeja from the past that could give rise to a new bhava (and birth), none of those will be grasped (upadana) at the cuti-patisandhi moment of an Arahant.
Even in regular kamma vipaka during a lifetime, one can live in such way as not to provide conditions for bad kamma beeja to bring fruits.
– For example, if one goes to a bad neighborhood at night, one may be setting up conditions for some bad kamma vipaka to materialize.
– Or, if one gets really drunk, one may be getting into arguments and even fights.
– I really cannot understand why people keep re-building houses in flood zones. They are likely to face the same situation again. It is again setting up conditions for another possible future disaster.
One should really contemplate on this point.