An endless list -- but among my favorites:

When a father helps a son, both smile; when a son must help his father, both cry.

When a young man marries, he divorces his mother.

With little children, little troubles; with big children, big troubles.

A man is not honest just because he has had no chance to steal.

A saloon can't corrupt a good man, and a synagogue can't reform a bad one.

If triangles had a God, He would have three sides.

"For instance" is not proof.

Safeguarding a girl in love is harder than guarding a sackful of fleas.

A rabbi whose congregation doesn't want to run him out of town isn't a rabbi; and a rabbi whose congregation does run him out of town isn't a man.