Sefer HaChinuch ספר החינוך

The negative commandment of “blessing” the Name: And it is from the roots of the commandment of “blessing” the Name that it empties out the man from any good, through this bad speech. And all the glory of his soul becomes something destructive, and he is considered like the animals. As it is with this exact thing through which God separated him for the good and with it man was created — and that is speech — [and] through which he is separated from the animals, that he is separating himself to evil. And he extracts himself completely from any parameter of knowledge and becomes like a disgusting and repulsive creeping animal, and lower than it. And therefore the Torah warns us about this — since the good God will desire our good. And each and every word that causes the denial of good to [a person] goes against God’s desire, may He be blessed.

Some of the laws of the commandment — for example, that which they explained that there is no guilt unless he pronounces the specific name, which is (yud-hei-vav-hei), or of (alef-dalet-nun-yud) according to the opinion of some commentators (Mishneh Torah, Laws of Foreign Worship and Customs of the Nations 2:7); that which they said (Sanhedrin 56a), that they would each and every day ask the witnesses with a nickname, “Yose should strike Yose,” when the case was finished they would move all the people outside and ask the senior witness and say to him, “Say with your mouth what you heard,” and he would say [it], they would [then] stand on their feet and tear [their clothing] and not [ever] mend [them], and the second witness would say, “I also heard like him,” and if there were many witnesses, they all say like this; that which they, may their memory be blessed said (Nedarim 87a), that the blasphemer, even though he recants within the time of speaking (right away) is [still] stoned; that one who curses God in the name of idolatry is to be attacked by zealots, but if they did not attack him and he comes to court, he is not stoned unless he “blesses” with a name from the specific names [of God], and the reason he is not stoned is because, even at the time of his anger, he himself knows that his words are complete foolishness, but zealots attack him nonetheless, since he was destructive and caused abomination and was brazen-faced to speak bad things like these; that which they said that anyone who hears the “blessing” of God from the mouth of an Israelite is obligated to tear [his clothes], but that one who hears it from a gentile is not obligated to tear, and Eliyakim and Shevna only tore because Ravshakeh was an apostate (Sanhedrin 60a); [that] all of the witnesses and the judges lean their hands one by one upon the head of the blasphemer and say to him, “Your blood is upon your head, since you caused [it to] yourself,” and there is none else in all of those killed by the court besides only the blasphemer that we lean upon, as it is stated (Leviticus 24:14), “and all those who heard lean, etc.”; and the rest of its details — are [all] elucidated in Sanhedrin, Chapter 7.

And this prohibition is practiced in every place and at all times. And one who transgresses it and “blesses” the Name, in the way we said, is stoned in the Land by the mouth of ordained judges. And today, outside the Land — where we do not have ordained judges — all of Israel distance themselves from him and place a ban upon him. (See Tur, Choshen Mishpat 27.)