him, hymn

Him or him is the objective form ( action is done to the person or thing ) of  "he"--
Give the sandwich to him.
I asked him, but he didn't know.

Hymn or hymn ( rhymes with him ) means a song about ( or to ) God--a religious song--
The cantor taught the congregation a new hymn.
We hear this old hymn on the radio a lot at Christmas time.

Now that you know that, you can say--
"There's the choir director. Ask him if he knows this hymn."

Note--a book of hymns is called a "hymnal"--
If you'll turn to page 100 in your hymnal...