John Gill Commentary 2 Kings 9:24

"And Jehu drew his bow with his full strength, and smote Joram between his arms; and the arrow went out at his heart, and he sunk down in his chariot." — 2 Kings 9:24 (ASV)

And Jehu drew a bow with his full strength
To give the arrow all the force he could;

and smote Jehoram between his arms ;
that is, between his shoulders, his back being turned to him, and the chariot an open one:

and the arrow went out at his heart :
quite through him:

and he sunk down in his chariot ;
and died immediately.