Megillah 4:8-9

Megillah 4:8

If a person refuses to lead the service while wearing colored clothes, he should not be permitted to do so even when wearing white. If he refuses to lead when wearing sandals, he should not be permitted even when barefoot. If a person makes round tefillin, he has endangered himself and not fulfilled the mitzvah. If a person wears his tefillin on his forehead or on the palm of his hand, it is a sign of heresy. If one covers his tefillin with gold and wears them over his sleeve, he is imitating those who oppose the teachings of our Sages.

Megillah 4:9

One who says in prayer, “May the good bless You” acts like a heretic. If one says, “Your mercy extends to the bird’s nest” or “May Your Name be remembered for good,” or if he says “Modim modim” (i.e., twice), he is to be silenced. Also, whoever interprets Leviticus 18:21 (the prohibition of the service of Molech) as a prohibition against procreation with an Aramite woman, he is silenced and reprimanded.