At that time Jesus went through the wheat fields on the Sabbath. His disciples were hungry so they were picking heads of wheat and eating them.
References for Matthew 12:1
When the Pharisees saw this, they said to him, "Look, your disciples are breaking the Sabbath law."
But he said to them, "Haven't you read what David did when he and those with him were hungry?
He went into God's house and broke the law by eating the bread of the presence, which only the priests were allowed to eat.
Or haven't you read in the Law that on the Sabbath the priests in the temple treat the Sabbath as any other day and are still innocent?
But I tell you that something greater than the temple is here.
If you had known what this means, I want mercy and not sacrifice, you wouldn't have condemned the innocent.
References for Matthew 12:7
The Human One is Lord of the Sabbath."
References for Matthew 12:8