Upvote:0
FYI it's not clear to me that the objects were stolen (i.e. that the act was "stealing"):
It might be arguable that the items didn't "belong to" Buddhaghosa -- not that I want to argue that, but there have been previous discussions on this site about whether the Buddha-Dhamma "belongs to" anyone in particular.
According to the Vinaya (quoting from here),
The act of taking what is not given, even when one perceives it as not given, counts as theft only if oneβs intention is to steal it. Thus, as the non-offense clauses say, a bhikkhu incurs no offense if he takes an object temporarily or on trust.
According to the quote in the OP this wasn't exactly "on trust" but it was, clearly, only "temporarily".
Upvote:0
According to Mahavamsa, It it because the god wanted to show others that the venerable Buddhaghosa was competent enough to translate the ancient Sinhala commentary.
Ven. Buddhaghosa was said to had re-written it again three times without even a spelling mistake, so that the Sangha in Mahavihara could be able to conclude that he was competent enough.
Upvote:2
To be sure of something, we often double-check. And to be extra sure we triple-check. For example, consider solving a math problem. If we only solve the problem once, we are not quite sure we did it correctly. There are many steps in a math problem and they ALL have to be correct. What should we do?
Well, if we start with a clean slate and solve the problem again in its entirety and arrive at the same answer, then our confidence increases. Double checking improves confidence. And triple-checking from a clean slate provides us even more assurance of correctness, especially if all three answers agree exactly.
Note that for thorough checking we don't merely glance at our first answer. Instead, we start from a clean slate and do the entire problem once again. Such care and caution is commonly exercised when we, for example, build rockets that should not blow up. When a single O-ring fails, a rocket can destroy lives. We have to be mindful of every single part of our answer.
So it can be understood that Sakka here is simply helping out by "stealing" the thrice-written book to give Buddhaghosa a "clean slate". And by writing the exactly same thing three times over from a blank slate, Sakka has helped prove Buddhaghosa's deep and clear knowledge. In fact, the books are returned for that very same verification. By "stealing" the books, Sakka proved that Buddhaghosa was relying on mindful memory instead of simply copying what he had already written.