Matrix.Identity(n) returns an identity matrix of size $n\times n$.
If the option “Userdata” is set to false (default is true) the output is returned as a table of tables rather than a pointer (compare Matrix.ToUserdata() and Matrix.ToTable()).
print(Matrix.Identity(3))
{ { 1 , 0 , 0 } , { 0 , 1 , 0 } , { 0 , 0 , 1 } }