It is implied that they did things without waiting to find out what Yahweh wanted them to go. AT: "they did things without first waiting for Yahweh's instructions" (See: [[rc://en/ta/man/translate/figs-explicit]])
Here David speaks about Yahweh causing the people to be afflicted by a disease as if Yahweh sent a disease to them in the same way that someone sends a person or a messenger. AT: "but he caused them to suffer from a horrible disease" (See: [[rc://en/ta/man/translate/figs-metaphor]])