This script shows matching lines with their line numbers:

use strict;
use 5.010;

sub file_to_arr {
    my $fil_name = shift;
    open my $fh,$fil_name
        or die qq(Some error when opening file "$fil_name": $!);
    my $rslt;
    while (<$fh>) {
        s/[\n\r]//g; # removing CR and LF symbols
        next unless $_; # skipping empty lines
        push @$rslt,[split /\s+/];
    }
    return $rslt;
}

my ($arr1,$arr2) = (file_to_arr('3.txt'),file_to_arr('4.txt'));
for (my $i = 0; $i<=$#$arr1; $i++) {
    if (@{$arr1->[$i]} ~~ @{$arr2->[$i]}) {
        printf "%s: %s\n",
            $i+1,
            "@{$arr1->[$i]}";
    }
}
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