Bread of deceit. Bread gained by deceit. Genitive of Origin. See App-17 (2).
Bread. Put by Figure of speech Synecdoche (of Part), for all kinds of food.
deceit. lying. Hebrew. sheker. See note on Proverbs 11:18.
filled with gravel: or grit. See note on Genesis 3:14, implying utmost disappointment. See App-19.