Matthew 13:25,26 - Ellicott's Commentary On The Whole Bible

His enemy came and sowed tares. — The act described was then — and still is — a common form of Eastern malice or revenge. It easily escaped detection. It inflicted both loss and trouble. The “enemy” had the satisfaction of brooding for weeks or months over the prospect of the injury he had inflicted, and the vexation it would cause when discovered. The tares, known to botanists as the Lolium temulentum, or darnel, grew up at first with stalk and blade like the wheat; and it was not till fructification began that the difference was easily detected. It adds to the point of the parable to remember that the seeds of the tares were not merely useless as food, but were positively noxious.