I have a pergunta for you. Why is a Latin expression „per omnia sæcula sæculorum”, used in so many prayers, been translated into English as „world without end", instead of „for all ages", or „for all eternity” as it should be?

There is no word „mundus”, as in „mundi”, or „mundum”, meaning „world”, ever been mentioned in the original Latin expression of any related prayer, so, I was wondering how and when did people start using the English expression „world without end”, because „sæcula” means „centuries”, or „ages”, therefore, it's a synonym for „eternity”, yet this world of ours is not eternal, so, why not translating this Latin expression mais literally, like this: „in/through all ages”, or even better „in/through all eternity”? That would have a lot mais sense! I just wanna know whose idea was it to come up with an English expression „world without end” and when and why was it first invented, instead of a mais logical and a mais literal translation. I'm no expert in English. It's not even my native tongue, so, can somebody please answer this simple linguistic pergunta of mine? Thank you.