How to join arrays with a common one

PHP
8

Ok I made this change on your code and it worked:

<?php 
//for overview.php

$bk2=2;
$ch2=30;


$sqlSummary = "SELECT * FROM ".strtolower($bookTitle[0]).$chapter[0]." WHERE rel_book_title = 'Genesis' AND rel_chapter = '8' ORDER BY ".$recordType[0].$chapter[0]."_ID ASC";

$resultSummary = $db->query($sqlSummary);

// Step 4: Iterate over the results
while($rowSummary = $resultSummary->fetch(PDO::FETCH_ASSOC)){
    $idSummary[] = $rowSummary[$recordType[0].$chapter[0]."_ID"];
    $datetimeSummary[] = $rowSummary['date_time'];
    $bookSpokeSummary[] = $rowSummary['book_spoke'];
    $chapterSpokeSummary[] = $rowSummary['chapter_spoke'];
    $relBookSummary[] = $rowSummary['rel_book'];
    $relBookTitleSummary[] = $rowSummary['rel_book_title'];
    $relChapterSummary[] = $rowSummary['rel_chapter'];
    $summarySummary[] = $rowSummary['summary'];
    $url_linksSummary[] = $rowSummary['url_links'];
}
//print_r($summarySummary);

$rh = explode(";", $summarySummary[0]);
//print_r($rh);

$array1 = array();
for($c=0;$c<count($rh);$c++){
    $rhd = explode("-", $rh[$c]);
    for($d=0;$d<count($rh[$c]);$d++){
        //echo $rhd[1]."<br />\n";
        array_push ($array1, $rhd);
    }
}

//var_export ($array1);

if ($array1)
{
    $array2 = array();

    foreach ($array1 as $i)
    {
        $color = $i[1];
        //$a = array (trim ($i[2]), $color);
        $a = array ($i[0], $i[1]);
        if (isset ($array2[$color])) $array2[$color][] = $a;
        else $array2[$color] = array ($a);
    }

    foreach ($array2 as $i) $keyword_colorArr[] = $i;
}

//var_export ($keyword_colorArr);

$commentsarray = array(
"",
"",
"",
"",
"",
"",
"",
"",
"",
"",
"",
""
);

$highlight = array(
array(array("they that","black"))
);

give();
?>

However if I want to join other arrays how can I express within the code? I also want to associate $highlight to the 2nd array.