The meaning of "Grab hold there"

[symaa]

Hello,

Could you please explain me the sentence in red:
(sometimes and especially in conversation sentences seem to be confused when the order or the structure of it :subject/Verb/compliment are changed.)

WILLY: Chevrolet, Linda, is the greatest car ever built. (To the
boys.) Since when do you let your mother carry wash up the
stairs?
BIFF: Grab hold there, boy!
HAPPY: Where to, Mom?
LINDA: Hang them up on the line. And you better go down to
your friends, Biff. The cellar is full of boys. They don’t know
what to do with themselves.


Thank you in advance.

Regards

[symaa]

Would you please rewrite the sentence in red more easily?

Thank you

[5jj]

Could you please explain me the sentence in red:
(sometimes and especially in conversation sentences seem to be confused when the order or the structure of it :subject/Verb/compliment are changed.)

WILLY: Chevrolet, Linda, is the greatest car ever built. (To the
boys.) Since when do you let your mother carry wash up the
stairs?
BIFF: Grab hold there, boy!
HAPPY: Where to, Mom?
LINDA: Hang them up on the line. And you better go down to
your friends, Biff. The cellar is full of boys. They don’t know
what to do with themselves.

It's very difficult to say exactly what the line means without more context; we really need see the situation on video.

It could be that Biff is taking hold of one end of the basket of washing, and is urging someone else, possibly Happy, to take hold of the other end.

[symaa]

It's very difficult to say exactly what the line means without more context; we really need see the situation on video.

It could be that Biff is taking hold of one end of the basket of washing, and is urging someone else, possibly Happy, to take hold of the other end.

Thank you teacher. It was extracted from "Arthur Miller's Death of a salesman, act one"
I usually find such vague expressions that impede the comprehension of the text like that.

WILLY: Sweetheart!
LINDA: How’d the Chevvy run?
WILLY: Chevrolet, Linda, is the greatest car ever built. (To the
boys.) Since when do you let your mother carry wash up the
stairs?
BIFF: Grab hold there, boy!
HAPPY: Where to, Mom?
LINDA: Hang them up on the line. And you better go down to
your friends, Biff. The cellar is full of boys. They don’t know
what to do with themselves.
BIFF: Ah, when Pop comes home they can wait!
WILLY (laughs appreciatively): You better go down and tell them
what to do, Biff.
BIFF: I think I’ll have them sweep out the furnace room.
WILLY: Good work, Biff.

Thank you.