Sirach says that he was like a little channel from a river. He used that water to irrigate his garden and flowers. Then the channel became a river and the river became a sea. His instructions shined forth like the dawn of a new day. The brightness could be seen from a long distance away. His teaching was like prophecy for all future generations. He was not working for himself, but to give instructions to all seeking it.
Sirach wanted his readers to listen to his instructions about their mouths. Do not get caught up by saying something you might regret. It is usually the words that you utter from your mouth that causes problems for sinners, revilers, and the arrogant.