משלי כב:ו פירוש: רש״י וMetzudat David

Train a child According to what you teach a child and train him in matters, either for good or bad, even when he grows old, he will not turn away from it.

Start to accustom the boy in his [early] years to the service of God through wisdom in things small and big; once he is accustomed to serving God well, when he grows old he will not stray [from the path] because his deeds will be enlightened.