$contact->phoneNums()->delete();
foreach(...){
//добавляем из массива
}
<?php if($contact['id'] == $number['contact_id']): ?>
<option value="phone-number">
<?php echo $number['phone_number'];?>
</option>
<?php endif;?>
<?
$arr_numbers = array();
foreach ($contacts as $contact)
{
foreach ($numbers as $number)
{
if($contact['id'] == $number['contact_id']) $arr_numbers[]= $number['phone_number'];
}
}
?>
<?php if(count($arr_numbers ) > 0): ?>
<select phones="phones">
<?php foreach ($arr_numbers as $number):?>
<option value="phone-number">
<?=$number['phone_number'];?>
</option>
<?php endforeach;?>
</select>
<?php endif;?>