I was looking for a large PDF file that was above 100 MB. The file was inside thousands of other files and folders, so I used this command to find it:

find . -type f -size +100M | grep -i pdf

The above simply used the find utility and specified that this is a file and that file is > 100 MB, then I used grep to filter PDF files, that’s it!

Enjoy!

Sources:
https://ostechnix.com/find-files-bigger-smaller-x-size-linux/