Using に to indicate purpose without a movement verb


I found the following sentence in the iknow core 1000 step 9:

[![enter image description
here](https://i.stack.imgur.com/EfRrd.png)](https://i.stack.imgur.com/EfRrd.png)

> 夕食に牛肉を買った。 I bought beef for dinner.

に is marking the purpose of buying beef?




に is for _for_ in that sentence. So yes, it's marking purposes of buying beef.

