Why is Nibbana referred to as "The destination and the path leading to the destination"?

Why is Nibbana referred to as "The destination and the path leading to the destination" ? What does this mean? Is it referring to the cessation of defilements? Is it referring to anything other than the cessation of defilements? In what way is Nibbana "...the path leading to the destination" ? reference: https://dhammawiki.com/index.php/Nibbana#33_synonyms_for_Nibbana