Caught in the cage of words

Have you ever looked at things around you closely? Me neither. That changed when I started my journey with languages. My first ever aha-moment was when I learned the word "window" in Persian. It's پنجره  /paenjareh/. It sounded familiar to my ears and that for no reason. In Punjabi پنجره  ਪਿੰਜਰਾ /piñjraa/ means "cage"! Isn't that fascinating? At least I thought that was a revelation.

Therefore I had to dig deeper. Where does پنجره  stem from? and why do Persians have a different understanding of it than Punjabis? First I had to find out what Persians call "cage", and that was totally unfamiliar for me. They call it قفس /qaefaes/ which probably is derived from Arabic. While in Punjabi "window" is ਬਾਰੀ, ਟਾਕੀ /baari, Taaki/. None of these resonated with the Persian version. 

Turkmens, Turks, Azeris they all have a version of پنجره but not the Arabs... Then I asked for some help and learned that the word for "cage" in Sanskrit is पञ्जरम् /pañjaram/. That at least confirms that ਪਿੰਜਰਾ is derived from Sanskrit.

Between Sanskrit, Persian, and Arabic, Sanskrit seems to be the oldest language but that would also depend on who you asked. I conversed with an Iranian and he claimed that in fact, Persian is an older language. This information didn't really solve the puzzle.

Unfortunately, I was not successful in finding out why the Persians call "window" پنجره. I could possibly just be romanticizing the journey of these words. It could be as simple as that a dervish just decided to call "window" پنجره because of his interpretation and if we look at windows they could remind us of modern cages. That is the only possible meeting point I could think of. 

Painting: "Woman with birdcage in window" by Clifford Hooper Rowe

Maybe any of you reading know more about the etymology of the same words? I would love to read your thoughts about it.