“And your food which you will eat will be by weight twenty shekels a day. Each day at the same time you will eat it.”
Twenty shekels would come to about 225 grams (eight ounces). This was minimum rations indicating siege rations. ‘Each day at the same time you will eat it.' The Hebrew is literally ‘from time to time' but compare the similar use in 1 Chronicles 9:25. It seems to signify a recurring action taking place at the same time each day. The purpose of this was to make it a recognised activity in front of those who came to observe his behaviour.