While today’s readings are short, they are a slice of life picture of Jesus' time and there is a lot more to it than there first appears. For instance if you walked through a grainfield today picking heads of wheat and eating them, you might be walking on private property and stealing. Jesus and the disciples were doing neither of these things. Ancient well-used paths alongside or through fields, were used by everyone and the areas alongside those paths were areas that the poor, widows and travellers, like Jesus and his disciples. They were “allowed” under the Law of Moses to “glean” from these areas, and property laws were different back in Jesus' time. What he is accused of is “working on the Sabbath”, but what he and the disciples were doing was allowed, under God’s law.
Just as it was not considered stealing because they were not using a sickle, it also was not really considered work. But this was not a shouting match with accusations or an argument, in a court of law, this was a rabbinic style debate with some Pharisee’s that were walking with him and his disciples and treating him as a Rabbi and he was teaching them as a Rabbi. In early Judaism debating Torah arguments was supposed to be going on “when you walk by the way” between Rabbi and students and was a form of teaching/learning, and Jesus’ response to the argument is classic rabbinic debate at its best.
Instead of bringing up the law in Dueteronmy, Jesus has something more important to teach them. He brilliantly quotes the prophets to them, reminding them of the time that when King David and his men were on the run and very very hungry the high priest at the time gave David God’s bread, that only Priests of the Lord were supposed to be allowed to eat. It is a simply brilliant comparison, David was anointed by God (like Jesus) the leader of companions for whom he also needed food, (like Jesus), David’s life was being threatened by the ruling authority of the day (Like Jesus), David’s MIGHTY MEN was a motley crew of untrained, outcasts and outlaws (Much like the disciples). David was allowed this because it was recognised by Jews that the preservation of human life ranks above Sabbath observance in order of importance. In fact Jesus points out later, that if your sheep/cattle fall into a pit on the Sabbath and would die, you are allowed to work to pull them out. (Matthew 12: 11-12). So preservation of all life in general ranks above the Sabbath laws. Even the early rabbis understood eating as essential to sustaining human life.
From this we can know that preservation of life, especially human life, made in his image, is more important to God than religious rules. Jesus time and again pointed out to them that mercy, justice, and taking care of others, the poor, widows, orphans and those in need was what the Father values above all.