In "My Life had stood," the theme of mortality is closely tied to the transition from life to death. The speaker wrestles with the idea of death approaching (whether suddenly or slowly). In some ways, she tries to look past death into the unknown. In this poem, we watch our speaker contemplate how easily life can be taken away, while she considers her own role in either preserving or destroying life.
The power to kill functions as a distraction from the speaker’s own mortality.