Sit on (one's) hands 置之不理
When we needed help from Mary, she just sat on her hands.
(one's) hands are tied 受到限制
I'm sorry. There's nothing I can do. My hands are tied.
Know sth. like the back of your hand
You should ask Samantha for directions—she knows this city like the back of her hand.
Live hand to mouth 勉强度日
He has a wife and two children and they live from hand to mouth on what he earns.
Win sth. hands down 轻松取胜
They are a strong team and they expect to win the game hands down.