It's an implied threat, which you can infer from the presentation of the information. For example:

You really should listen to me. If you need some time to think it over, I understand. It's a lot to consider and you've got a lot in your plate. I'll check in soon - would tomorrow be okay? If you need more time, just tell me when.

vs

You really should listen to me. I'll give you a day to think it over before I take further action.

Same information, but the latter assumes a position of authority (I, the person in charge, will be the provider of the time you will receive), and then uses that position to provide an ostensible benevolence as a way to mitigate the implied follow up of non-benevolence. The threat is introduced as the power disparity. The person in power has leverage over the less powerful and the threat is that they will use it. Remove the power disparity, and the implication of threat is also removed.

Unions also use the threat of striking as a leverage point against corporations. As I noted elsewhere in this thread, there seems to be a common fallacy in this thread of "threat = bad". Laws are threats too. You need a more convincing argument than this.