King James Version
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.English Standard Version
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.New International Version
so that it will not be obvious to men 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.