Question:
In regards to borer on shabbos, may one prepare food that involves separation and then immediately walk to another person’s house to bring the food to them to eat? Similarly, may one separate a sefer from a mixture of seforim (assuming they are mixed in a way that would be defined as a halachic “mixture”) and then immediately walk to the beis midrash to learn from it there? If these activities are prohibited because they wouldn’t be considered “miyad” due to the delay involved in actually using the separated items, then why would it be permissible to separate food (in the above case) and then walk over to the table to eat it there, or why would it be permissible to separate the sefer (in the above case) and then take it to one one’s table to learn from it there, since in both cases a delay (albeit a shorter one) is still taking place?
Answer:
If you are preparing the salad and then immediately walking to where you are going and starting the meal right away then it would seem that it is all part of the actual preparation of the item. The item needs to be cut up and brought to the place it is being eaten. The same would be for the sefer, its preparation is to take it off the shelf and bring it to where you are going to learn with it, and if it part of one process it would be considered miyad. The opinion of the Chazon Ish though is that if it takes longer than half an hour it is no longer considered miyad.
Best wishes
