Matthew 6:18

that your fasting may not be seen by others but by your Father who is in secret . And your Father who sees 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.

That thou appear not unto men to fast, but unto thy Father which is in secret : and thy Father, which seeth in secret, shall reward thee openly.