Reference for Sanhedrin 21:2
עמד שמואל הקטן ואמר אני הוא שעליתי שלא ברשות ולא לעבר השנה עליתי אלא ללמוד הלכה למעשה הוצרכתי אמר לו שב בני שב ראויות כל השנים כולן להתעבר על ידך אלא אמרו חכמים אין מעברין את השנה אלא במזומנין לה ולא שמואל הקטן הוה אלא איניש אחרינא ומחמת כיסופא הוא דעבד
said: 'Send me up seven [scholars] early in the morning to the upper chamber<span class="x" onmousemove="('comment',' The meeting place of the Rabbis. v. Keth. 50b; Shab. Ch. I, M. 4. [V. Krauss, Lewy-Festschrift, pp. 27, ff.]. ');"><sup>3</sup></span> [for this purpose].' When he came in the morning and found eight, he asked: 'Who is he who has come up without permission? Let him go down.' Thereupon, Samuel the Little arose and said: 'It was I who came up without permission; my object was not to join in the intercalation, but because I felt the necessity of learning the practical application of the law.' Rabban Gamaliel then answered: 'Sit down, my son, sit down; you are worthy of intercalating all years [in need of such], but it is a decision of the Rabbis that it should be done only by those who have been specially appointed for the purpose.' — But in reality it was not Samuel the Little [who was the uninvited member] but another;<span class="x" onmousemove="('comment',' [Probably R. Eliezer b. Hyrcanus, v. Bacher; Agada der Tanaiten, vol. I, p. 84.] ');"><sup>4</sup></span>