'Slackness' in the Bible

from the sound of the stamping of the hoofs of his stallions, from the clattering of his chariots, the noise of their wheels. Fathers do not turn to [their] children because of [the] slackness of [their] hands.

“Cursed is the one who does the work of the Lord negligently,And cursed is the one who restrains his sword from blood [in executing the judgment of the Lord].