Ramona Freedman wrote:

Dear Rabbi,

I am wondering where it is written that the notion of internal peace is like a peaceful home.

Dear Ramona Friedman,

In Eichah Rabba there is an interesting parable which perhaps alludes to internal peace vis-a-vis a peaceful home. A king was in a rage, and walked out angrily from his palace. When he was outside [and calmed down], he kissed the wall of his palace and said, "Let there be peace inside my palace; peace inside my kingdom house. Peace inside my dear home. Let there be peace from now on; let there be peace..."

Sources:

• Eichah Rabba, Petichta 25