What is one to do if on a day of three Sifrei Torah there are only two scrolls available?[1]
If there are only two Torah scrolls available, then one is to read the Parsha of Rosh Chodesh from the second scroll, and read the extra Parsha from the first scroll. [This however only applies if the first scroll is rolled to the extra Parsha prior to it being needed for the third reading.[2] If however the first scroll was not rolled to the extra Parsha prior to it being needed, then it is better to read the extra Parsha from the second scroll.[3] Seemingly, however, if the extra Parsha is adjacent to the weekly Parsha, such as by Parshas Shekalim, then one is to read from the first scroll even if it was not rolled to the extra Parsha prior to Hagbah.[4]]
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[1] Rama 669:1 “In a place where they have only two Torah scrolls, they read in the first one V’Zot HaBerachah, and in the second one Bereishit. Then they return and take the first one again for the reading of the day. And this is what should be done in every place where three Torah scrolls are required but only two are available.”; Peri Chadash 684; Shulchan Gavoa 684:11; Shaareiy Efraim Shaar 8:6; Kaf Hachaim 684:16; Mikraeiy Kodesh 2 29:28
[2] When to roll it? Some Poskim rule that it should be rolled while the second Torah scroll is being read. [Shalmei Chagiga Inyan Kerias Hatorah Bemoados Simchas Torah 134 in name of Emes Leyaakov] Other Poskim, however, write that it is improper to do so being that it will distract the people rolling it from listening to the second reading, and therefore it should be rolled while the Mi Shebeirach is being recited. [Shaareiy Efraim Shaar 8:6; Mikraeiy Kodesh 2 29:28; Shulchan Hakeria 21:20; Yikra Detzibura p. 381]
[3] Chemed Moshe 669; Kaf Hachaim 669:41; Biur Halacha 669:1 “Vechozrim” “This applies specifically when it has already been rolled to that place, so that the congregation will not need to wait. But otherwise, it is better to roll the scroll that is already placed there, and not to transgress the principle of ein ma’avirin al ha‑mitzvot (one should not pass over a mitzvah), and to take the first one. — Chemed Moshe”
[4] See Salmas Chaim 359
The reason: As Shekalim is read from Ki Sisa which is in proximity to the weekly Parsha, while Rosh Chodesh is read from Pinchas which is very distanced from Ki Sisa, and thus in this situation, seemingly even according to the Chemed Moshe ibid one should read Shekalim from the first scroll.
