Sanhedrin 66A

״אל תתחיל בי״, ״שחרית הוא״, ״ראש חודש הוא״, ״מוצאי שבת הוא״.

The term is also referring to one who says to a collector of charity: Do not collect from me first, as that is a bad sign for me; or: Do not collect from me now because it is morning, and it is a bad sign to begin the day with a loss; or: Do not collect from me now because it is Rosh Chodesh, and it is a bad sign to begin the month with a loss; or: It is the conclusion of Shabbat and I do not want to begin the week with a loss.

תנו רבנן: ״לא תנחשו ולא תעוננו״⁠ – כגון אלו המנחשים בחולדה, בעופות, ובדגים.

A baraita states that the verse: “Nor should you practice divination nor soothsaying” (Leviticus 19:26), is referring, For example: to those who divine and receive guidance according to what happens to a weasel, to birds, or to fish.

מתני׳ המחלל את השבת בדבר שחייבין על זדונו כרת, ועל שגגתו חטאת.

Mishnah: Also liable to be executed by stoning is one who desecrates Shabbat by performing a matter that for its intentional performance one is liable to receive karet and for its unwitting performance one is obligated to bring a sin-offering.

גמ׳ מכלל דאיכא מידי דחילול שבת הוי, ואין חייבין לא על שגגתו חטאת ולא על זדונו כרת.

Talmud: By inference, there is another matter that is a desecration of Shabbat, and it is prohibited by the Torah, but for its unwitting performance one is not obligated to bring a sin-offering, nor does one receive karet for its intentional performance. Otherwise, the statement in the Mishnah that one is liable for desecrating Shabbat for performing an act for which one receives karet or is obligated to bring a sin-offering would have been superfluous.