The gemarah in Beitza discusses the possibility of moving an egg in yom tov in order to make it safe. In addition, the reverse, moving a plate and using it to protect the egg, in effect just covering the egg with a protective covering, is also contemplated at length
in meseches eruvin and meseches shabbos when discussing the case of saving tefilin found in reshus harabim, there the gemarah also offers the possibility of covering the tefilin as a way to safeguard them.
I am puzzeled as to why in beitza the solution to cover is problematic and discussed at length while in eiruvin / shabbos the solution to cover is accepted without discussion. Both cases involve utilizing a non-mukktza item and covering a muktza (maybe) item with it.
Thank you for all your efforts
Efraim Goldstein, New York, USA
It seems to me that the contemplation at length in Beitzah is more regarding the Sugya of Davar Sheyesh Lo Matirin. The main place where the topic of Muktzah is discussed regarding utilizing a non-Muktzah item to cover a Muktzah item is in Shabbos (43a), where Rebbi Yitzchak's statement that one may not do so (unless there is a case of Tzorech Mekomo) is discussed at length. [In any event, there are times when we say "Divrei Torah Aniyim b'Makom Echad v'Ashirim b'Makom Acher," -- "words of Torah are poor (not spoken about at length) in one place and rich in another place."]