Why is no second Torah scroll taken out on Shabbat to read the Musaf portion ('U'veyom HaShabbat')?

ShabbatTorah Reading

Synopsis

On Shabbat, unlike Yom Tov and Rosh Chodesh, no second Torah scroll is taken out to read the Musaf sacrifices portion. Multiple reasons are given by the authorities.

Early Acharonim
Late Acharonim
Lenient
Strict
Lesser cited
Major authority

Discussion

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