During Passover of 1944, there was no matzah (unleavened bread) available at the Bergen-Belsen concentration camp. Since the rabbis would not permit the inmates to endanger their lives by fasting, they decreed that hametz (leaven) could be eaten, provided that the following prayer be recited before each meal.
Our Father in Heaven, behold it is evident and known to Thee that it is our desire to do Thy will and to celebrate the festival of Passover by eating matzah and by observing the prohibition of leavened food. But our heart is pained that the enslavement prevents us and we are in danger of our lives. Behold, we are prepared and ready to fulfill Thy commandment- “And you shall live by my commandments and not die by them.”
We pray to Thee that Thou mayest keep us alive and preserve us and redeem us speedily so that we may observe Thy statutes and do Thy will and serve Thee with a perfect heart. Amen.
Source- Ronald H. Isaacs and Kerry M. Olitzky. Critical Documents of Jewish History, a Sourcebook. Jason Aronson Inc. Northvale, NJ. p. 49.