Rav Beruna was a student of Rav, and from his practice people knew what Rav held: Yevamot 110a
Rav Beruna cited a lesson taught by Shemuel, and Rabbi Elazar couldn't believe Shemuel had said it. Rabbi Elazar challenged Rav Beruna to show him where Shemuel was staying, which he did. R; Elazar asked Shemuel whether he had said it, and Shemuel confirmed it. Rabbi Elazar challenged the lesson based on another of Shemuel's statements, and Shemuel was silent; it was unclear whether Shemuel had accepted Rabbi Elazar's point.: Eruvin 74a-b
Rav Beruna cited a lesson taught by Rav, and Rabbi Elazar couldn't believe Rav had said it. Rabbi Elazar challenged Rav Beruna to show him where Rav was staying, which he did. R; Elazar asked Rav whether he had said it, and Rav confirmed it. Rabbi Elazar challenged the lesson based on another of Rav's statements, and Rav explained the difference.: Eruvin 85a-b
