#!/usr/bin/perl

use strict; # https://perlmonks.org/?node_id=11132353
use warnings;

my @static = qw( 1 2 );
my $nonstatic = 3;

my @item = [];
@item = map { my $static = $_; map [ $static, @$_ ], @item } @static
  for 1 .. $nonstatic;

use Data::Dump 'dd'; dd \@item;
[download]

Outputs:

[
  [1, 1, 1],
  [1, 1, 2],
  [1, 2, 1],
  [1, 2, 2],
  [2, 1, 1],
  [2, 1, 2],
  [2, 2, 1],
  [2, 2, 2],
]
[download]