There, there!
Definition 1 of 1
Pro Tip 1/3Emotional Comfort
Use 'there, there!' to offer emotional support when someone is upset or distressed. 
There, there! It's just a bad day, not a bad life.
Pro Tip 2/3Patronizing Tone
Be cautious, as 'there, there!' can sound patronizing if the situation is serious. 
He tried to comfort her with a 'there, there!' but it sounded insincere.
Pro Tip 3/3Informal Use
The phrase is informal, suitable for casual conversations with friends or family, not formal settings. 
There, there! Let's go grab ice cream and forget this mess.