Halakhah zu Beitzah 3:10

The Shulchan Aruch (Orach Chaim 345:7) cites (and presumably accepts) the view that an area is a reshut harabim even without 600,000 people, although he does cite the other view as a secondary opinion.¹¹The Shulchan Aruch's view is somewhat unclear, as he appears to contradict himself in Orach Chaim (303:18). There he writes that no places today qualify as reshuyot harabim. Presumably, his reason is that he requires 600,000 people for a reshut harabim. Regarding the practice of Sephardic Jews today, see Yabia Omer (vol. 4, Orach Chaim 47:4) and page 7 of Rav Mordechai Eliyahu's comments to Rav Zechariah Ben-Shlomo's Hilchot Tzava. The Rama (O.C. 346:3) indicates that he accepts the requirement of 600,000.¹²This is inferred from the Rama's statement that in our day there are no reshuyot harabim. While logic would dictate that the Rama is writing this because he believes that only a place with 600,000 people constitutes a reshut harabim, this inference presents a certain difficulty. The Shulchan Aruch (Orach Chaim 303:18) also writes that there are no true reshuyot harabim, yet he appears to rule that 600,000 people are not required for a reshut harabim (O.C. 345:7). The Magen Avraham (345:7) points out this problem. Both the Magen Avraham (345:7) and the Taz (345:6) cite the view of the Ma'sat Binyamin (92) and the Maharshal (Yam Shel Shlomo, Beitzah 3:8), who rule that the presence of 600,000 people is not required. However, the Magen Avraham and Taz themselves disagree with these authorities and write that the majority view is that of Rashi, requiring 600,000 people. The Aruch Hashulchan (345:17) writes that the eruvin in the Jewish towns of Eastern Europe relied on this accepted leniency; otherwise, they could not have used tzurot hapetach.