at sb's disposal
to be ready or available to do something for someone with a great pleasure.
No worries dear Salwa, I am at your disposal at anytime.
If you would like me to do this work, I am at your disposal.
at sb's disposal
to risk a bad thing that is happening to you by doing something or assisting someone
Please dear Van Abdullah I'm going to put my head on the block for you.
I hope Van's boyfriend is going to have his head on the block for her.
have/put your head on the block
It is said when you do not understand something or even a word being said.
I don't like his classes because it's all Greek to me.
Salwa complained about her teachers because she said the lessons were all Greek to her.
It's all Greek to me