Restricting random matrices

[DrD]

I happened to discover that (in CAS) one could restrict lower and upper bounds of the random output by using something like:
randMat(3,3,x .. y), or ranm(3,3,x .. y), where x and y are integers. That hinted at other possibilities. Most of the things I tried did not succeed, however. So I am left to wonder what the real syntax is?