Board Thread:Questions and Answers/@comment-28067574-20190904162421/@comment-26907577-20190909175659

...That's not the point. The point is that the light-blue-SOUL-human died in the Ruins, but the light-blue-SOUL still reached Asgore.

Idea: Toriel knew the SOUL wouldn't survive forever on its own, so sent for a jar. It was reluctantly accepted on the condition that Asgore still get the SOUL.