How would I get a random array, if I am using multiple arrays from an object?

Ok, so I am new to Javascript. I have created an object with 3 separated arrays.

const messages = {
  message:[
   ["joke1","joke2","joke3"],
   ["tease1","tease2","tease3"],
   ["boost1","boost2","boost3"]
};

now I need to take a random message every time the user logs in. so for example:

 messages.message[0][2] or messages.message[2][0]

i cant get the second part of this code to work.

The first part was easy.

i was able to get the first random number from the array. that is put into the variable chooseArray1

here is where I am struggling.

const secondIndex = messages.message[chooseArray1[Math.floor(Math.random() * messages.message[chooseArray1])];

now Im getting an error here at the second [ in front of Math I cant seem to figure out how to get the random number of an array with an index.

I hope this makes sense. Apparently I have the coding skill of a rock.