Shabbos 70a: Chiluk Melachot

לרפואת האדמו"ר ר' יצחק מנחם בן גיטל מירל בריינדל לאה שליט"א בתוך שאר ח"י
ולזכות שמחה בן נעכא גיטל שיהיה כאחד הגדולים אשר בארץ

If a person knows that it is Shabbos and inadvertently performed numerous melachot he is liable for each and every one of them. This is affectionately called חילוק מלאכות. There is a geshmake chakira presented by the great Rav Menachem Zemba and many others in his footsteps: Must one warn a person not to do a melacha [התראה] by invoking that specific melacha or is it enough to warn him not to violate Shabbos.

The Achronim point to a Tosfos Rid [קלח] who is quite clear that one must invoke the specific melacha and a general warning is not enough. To quote [people tell me that they like the quotes on the blog although I am not sure that they mean these types of quotes:)]: פי' כיון דהבערה לחלק יוצאת כאילו
כתיב לאו אכל מלאכה ומלאכה דמי והו"ל כמו לענין דחלב
ודם שהן חלוקין זה מזה וצריך להתרות על החלב משום
חלב ועל הדם משום דם וכך על כל מלאכה ומלאכה
Peirush-Ally - The gemara derives from that fact that the Torah singled out the melacha of הבערה [kindling] on Shabbos that just as one is obligated for kindling individually, so one is obligated for every other melacha individually. So it is now as if the Torah had singled out each melacha and written "don't plant" "don't harvest" etc. and thus one must give התראה for each melacha specifically. This is just as one would give a separate התראה for the consumption of blood and forbidden fats which are are completely distinct prohibitions.

The question that one must ask on the Tosfos Rid is that the gemara offers another derivation of the rule of חילוק מלאכות and that is from the pasuk of אחת מהנה. It would seem that according to that pasuk one would NOT have to specify the melacha in his התראה. Why is that?

Rav Baruch Mordechai Ezrachi Shlita [ברכת מרדכי שבת כד] suggests that the limmud from הבערה teaches us not only חילוק מלאכות meaning that one is liable for each melacha separately but also that each melacha is in its own category as if it had been written explicitly in the Torah.

The limmud from אחת מהנה teaches חילוק מלאכות but not that each one is viewed as having been singled out by the Torah rather they are all subsumed under the general umbrella of "melachos Shabbos".  

In the sefer Minchas Aharon [ויקרא עמ' 586] he proves that Rashi and Tosfos argue with the Tosfos Rid and don't require an specified התראה

עיין עוד בתוצאות חיים סי' ה' סק"ב חידושי רבי שמואל בב"ק סי' ב' שו"ת הר צבי - טל הרים מבעיר סי' ב', שיעורי ר' דוד פוברסקי ב"ק ב:, חבצלת השרון ויקרא עמ' רכב מנחת חינוך מצוה לב סק"ב וזכורני שמו"ר דיבר על זה והובא בס' המה ינחמוני על שבת [ואיני יכול למצוא את הספר] ועוד ועוד