The Duties of the Heart, by Rabbi Bachye, tr. by Edwin Collins, [1909], at sacred-texts.com
Man's Obligation of Gratitude to God
IF man earns gratitude, reward and love for intermittent beneficence that is not unselfish, how great must be our obligation of service, gratitude and praise to the Creator of goodness, who therewith
causes all good, and whose goodness is without end and continuous, and is entirely free from all egoistic motive or intention, but is a pure freewill gift, and whose kindness is extended to all reasonable beings.