The seed is the Word of God. It was his own sad experience the Master was relating. The picture was of things, too, which had already happened in the case of many of his own true servants, the prophets.
It mirrored, too, the many future failures and the few future successes of the listening disciples; it warned them not to be deluded by appearances, not to be discouraged by apparent failure. The Word, of course, in the first instance is his own teaching; it comprehends, however, any preaching or teaching, whether of prophet of the past or minister of the future, winch tries faithfully to copy his own.