'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.

[The one who] does the work of Yahweh [with] slackness [is] cursed, and [the one who] keeps away blood from his sword [is] cursed.