Matthew 6:4, 6, 18

so that your giving may be in secret. Then your Father, who sees what is done in secret, will reward you.

But when you pray, go into your room, close the door and pray to your Father, who is unseen. Then your Father, who sees what is done in secret, will reward you.

so that it will not be obvious to others that you are fasting, but only to your Father, who is unseen; and your Father, who sees what is done in secret, will reward you.