expression
never mind that; don't worry about that
Used to dismiss a preceding statement or concern, often with a tone of reassurance or impatience.
「遅れてすみません」「いいから、早く座って。」
"Sorry I'm late." "Never mind that, just sit down quickly."
expression
listen up; just do it
Colloquial; used at the start of a command to add emphasis, like 'just' or 'come on'.
いいから、黙ってついてきて。
Listen up, just follow me without saying anything.