Search for a specific string inside a directory matching the files’ name

find . -name "articleTypes.xml" | xargs grep -n -i -e 'tidy'

or

find . -name "apple.txt" -exec grep -H -n -i -e "tidy" \{} \;

Search from the root all the files called ‘articleTypes.xml’ which contain the word ‘tiny’ and show in what line it occurs