Critics claim to find a contradiction between Exodus 21:2-11 and Deuteronomy 15:12-18, which allows Israelites to be kept as slaves for six years, and Leviticus 25:39-43, which says they may never be kept as slaves. They trace these inter-law differences to Israel having multiple, competing "legal traditions."

This rendering is flawed from the start because what the modern world calls "slavery" was effectively non-existent in the Biblical world; it was more akin to indentured servitude. Furthermore, critics fail to consider more prosaic and practical answers, such as the fact that Exodus was written for a nomadic society, while later laws were adapted for a society more settled in a fixed place. Hence, some laws were changed to suit their changing cultural and geographical surroundings, rather than representing contradictory legal traditions.