The Pharisees began to challenge Him regarding a different infraction of the Mosaic Law, that of reaping or gathering in crops (Exodus 34:21). This was an activity that was prohibited on the Sabbath so they demanded and explanation from Him regarding their behavior. Oddly they failed to see that there was no ingathering of any volume. They only took what they needed for personal consumption. Their demand for an explanation from Jesus reveals two issues. One, they failed to accept the Scriptures of the Law as authoritative emanating from God. They preferred to rest their complaint on their own legalistic non-biblical rules. Two, they were out to sabotage His work with the people by accusing Him of violating their laws. Jesus then gives the Pharisees an example of a similar incident from the Old Testament where genuine human need took a priority over ceremonial regulations.