Who congratulated Bilbo for giving bard the arkenstone?

In J.R.R. Tolkien's "The Hobbit," it is Gandalf who congratulates Bilbo Baggins for his decision to give Bard the Arkenstone. Gandalf appreciates Bilbo's bravery and wisdom in making a choice that could help prevent conflict over the treasure. This act of selflessness highlights Bilbo's growth throughout the story and his willingness to put the greater good above his own interests.