JSFiddle - React, Tailwind, and code Playground

HTML

<p>1</p>
<p>2</p>
<p>3</p>
<p>4</p>
<p>5</p>
<p>6</p>
<p>7</p>
<p>8</p>
<p>9</p>

CSS

div{
  background-color:red;
}

JavaScript

var $pArr = $('p');
	var pArrLen = $pArr.length;
	for (var i = 0;i < pArrLen;i+=3){
	      $pArr.filter(':eq('+i+'),:eq('+(i+1)+'),:eq('+(i+2)+')').wrapAll('<div />');
	};