[Idiom] what does "provide Muscle" means?

[Bahador]

hi there.
I was wathching movie.
narrator said : Jack provides the muscle.
it was about a group!
What does provide the muscle means?

 

[Raymott]

hi there.
I was wathching movie.
narrator said : Jack provides the muscle.
it was about a group!
What does provide the muscle means?

A group of what?
It seems to mean he does the heavy work.

 

[Bahador]

a Group for assassinate.
he had a grenade.

he wasn't leader.

 

[Anglika]

He's the one with the offensive weapon.

 

[Bahador]

He's the one with the offensive weapon.

can you explain more?

 

[Anglika]

You postulate a group of men who are planning an assassination. Only one has any form of effective weapon - the man with the hand-grenade so he is the one with the muscle. In fact, it seems that he ought to be the leader as he is the only one to have planned in advance.