core-bundle/src/Resources/contao/library/Contao/Model.php
public function originalRow()
	{
		$row = $this->row();

		if (!$this->isModified())
		{
			return $row;
		}

		$originalRow = array();

		foreach ($row as $k=>$v)
		{
			$originalRow[$k] = $this->arrModified[$k] ?? $v;
		}

		return $originalRow;
	}
public function originalRow()
	{
		$row = $this->row();

		if (!$this->isModified())
		{
			return $row;
		}

		$originalRow = array();

		foreach ($row as $k=>$v)
		{
			$originalRow[$k] = $this->arrModified[$k] ?? $v;
		}

		return $originalRow;
	}
Return the original values as associative array

@return array The original data