It's frustrating telling people what to do, isn't it?

You might ask, “Why didn't you do such and such?”  And they might respond, “But I thought you wanted so and so.”  Your frustration turns to anger.  You realize they assumed so and so because you didn't tell them everything.

Can’t they figure it out for themselves?

No.  They cannot read your mind.  You have to tell people what should be done––all of it.  Explain everything.  Who, what, when, where, why and sometimes how and how much. 

Be as clear as you can be, then ask them to repeat it back.  Allow for (if not beg for) questions, critiques, concerns, so you can tell it all. 

The part you don't tell them is the part that will tell on you in the end.

Consider a man named Cornelius, a soldier in charge of a battalion.  He was devout, someone who feared God, with his whole household.

Anything you leave out of your instructions, they will fill in for themselves.