Knock it off!

'Knock it off' is an informal way someone tells you to stop doing something. The person who says it has more power than you do. It's often said by a parent, or in an informal context.

Example:
-Hey you guys, for the last time, knock it off!
-Sorry, Dad!

Drop it

'Drop it' is something you say to end the topic of a conversation. Said as a direct command, it's most likely to be said by a parent to a child. Where the power relationship is closer, it is often asked, 'Can't we please just drop it?'

Examples:
-Mom, please can we stay up until 10? It's Saturday...!
-I've already said no, so drop it.

-Your aunt drives me crazy!
-I know. I'm sorry.
-I mean, she's always...
-Can't we please just drop it? We're almost to her house and I'm sure she's made a nice dinner for us!

All day

'All day,' as in "taking all day," or "I don't have all day" is a way to complain when you think something is taking too much time. It is usually said when the person being complained about is not within earshot, by a person who has power in a situation, or among close friends in informal situations.

Examples:

(To a friend while the salesperson in a store has stepped away) -What's taking all day?! It's just a simple return!

(To employees) -Come on, people! We don't have all day!

(To friends) -Come on, you guys! Let's go! I don't have all day!

Come-to-Jesus meeting

A 'come-to-Jesus' meeting is a meeting or talk where someone in power tells someone else what mistakes they're making and how they need to change. This expression most likely originated with the idea that traditional Christians have that Jesus came to earth to show people the error of their ways so they could change and be saved. Nonetheless, the expression is now used by the religious and non-religious alike, as a way to express that someone needs to have a talk with someone else before things get worse.

Example:
-I'm worried about my son. His grades are really slipping.
-Maybe it's time you had a come-to-Jesus meeting with him.