Dose of Halacha

Question: My teacher taught me that I mustn’t write on my hands. Is this forbidden in halacha ? Answer: The Mishna (Makkos 21a) teaches that there are two components of the prohibition of tattoos, scratching the skin and marking it with ink. If one just marked it with ink one has not transgressed the aveira (See Shulchan Aruch YD 180:1). Rambam (Avoda Zara 12:11) writes that if one only wrote but didn’t scratch the skin, one is pattur . Usually, when Rambam writes this it means that it is nonetheless prohibited miderabanan. The Minchas Chinuch (253:1) quotes Tosafos (Gittin 20b) and the Beis Shmuel (EH 124:16) who write regarding a slave with a divorce document tattooed onto him, that one mustn’t sign their signature onto their skin as doing so is assur mideraban . R’ Shmuel Wosner (Shevet Halevi 3:111:1) challenges this, however, writing that the Beis Shmuel was referring to when one had scratched one’s skin. If one were to fill an existing scratch with ink, one would transgres...

Question: I always us a cup as a kli sheni to fill up hot water to make coffee on Shabbos. Do I need to ensure that the cup is dry before using? Answer: Tosafos (Shabbos 40b) teaches that while a pot on a flame ( kli rishon ) retains its heat even after it’s been removed from the flame, a kli sheni cannot cook raw food placed into it. Tosafos (Shabbos 42a) writes that there is a machlokes as to whether iruy kli rishon , pouring from a kettle, is equivalent to a kli sheni, secondary container, or if it is considered to be cooking kdei klipa , the outermost food that it is poured over. R’ Ovadia Yosef (Yabia Omer OC 3:33:16) writes that there are rishonim who hold that it is the same as a kli rishon¸ while other rishonim hold that it is like a kli sheni . T he Shulchan Aruch (OC 318:10) writes that one cannot pour from a kli rishon onto spices. The Mishna Berura (318:74) explains that we pasken that iruy kli rishon cooks kdei klipa. R’ Yitzchak Meltzen (Shevisas Hashabbos...