Answer
The shifting of karma is a very specific process. It does not happen automatically. There must be willingness and a proper relationship for such an exchange to occur.
Srila Prabhupada gives a practical example.
Suppose you purchase vegetables from a shopkeeper and pay the proper price. Simply buying vegetables from him does not mean that his karma is transferred to you.
In ordinary dealings, people exchange services with one another. There are many kinds of interactions, but this should not be misunderstood as wholesale transfer of karma.
The transfer of karma in spiritual life is something unique.
For example, at the time of initiation, Srila Prabhupada explained that the spiritual master accepts the disciple's karma. This means the guru assumes responsibility for managing the disciple's karmic burden so that the disciple can advance in devotional service.
In return, the guru bestows spiritual blessings and elevates the disciple.
This principle also helps us understand the pastime of King Vena.
Why did the sages preserve a portion of his body before churning it?
Earlier verses explain that King Vena belonged to a noble royal lineage. There was genuine piety and spiritual merit within that dynasty.
Although Vena himself had corrupted that heritage through his sinful activities, the sages did not discard everything.
Instead, they separated the sinful contamination from the noble qualities that still remained within the lineage.
The purpose of the rishis was to extract and preserve the virtuous element that was still present in King Vena's lineage, which ultimately manifested in the appearance of the righteous King Prithu.
