You can only reference “it” for the innermost loop. Your code would need to be modified like so:
Put ("a", "b", "c", "d", "e") into letters
put (1, 2, 3, 4, 5) into numbers
repeat for each myLetter in letters
repeat for each item in numbers
log it && myLetter
end repeat
end repeat
There’s only one “it” variable and the value it is assigned in the outer loop gets overwritten by the iterator of the inner loop.