random number generation and two DO....END loops in sas

I need to Use SAS random number generation functions RAND() and a DO....END loop to create 100 obs in variable named X then I want to use another DO loop of 500 rounds to generate a total of 500 samples, each with 100 obs. a sample is basically sampling from a standard normal distribution.

I tried the following code but it does not give me what I need:

data A;
call streaminit(123);   /* set random number seed */
do i = 1 to 100;
X = rand("Normal");     /* random number generator */
 output;
end;

do r = 1 to 500 ;
if i then X = rand("Normal");
output;
end;
run;

Any input will be greatly appreciated.