John Lightfoot on Matthew 23:4

[Heavy burdens.] ...a heavy prohibition; Let him follow him that imposeth heavy things. There are reckoned up four-and-twenty things of the weighty things of the school of Hillel, and the light things of that of Shammai. "R. Joshua saith, A foolish religious man, a crafty wicked man, a she-pharisee, and the voluntary dashing of the Pharisees, destroy the world." It is disputed by the Gemarists, who is that crafty wicked man: and it is answered by some, "He that prescribes light things to himself, and heavy to others."