Responsa for Kiddushin 161:2
אמר רב יהודה אמר רב ל"ש אלא בעיר אבל בדרך עד שיהיו שלשה שמא יצטרך אחד מהם להשתין ונמצא אחד מתייחד עם הערוה נימא מסייע ליה מוסרים לו שני תלמידי חכמים שמא יבא עליה בדרך תרי ואיהו הא תלתא התם כי היכי דניהוו עליה סהדי
Two, and he [the husband] himself - that is three? - There it is in order that they may be witnesses against him.<span class="x" onmousemove="('comment',' If he cohabits, in which case she does not submit to the ordeal, v. loc. cit.');"><sup>3</sup></span> Rab and Rab Judah were walking on a road, and a woman was walking in front of them. Said Rab to Rab Judah, 'Lift your feet before Gehenna.'<span class="x" onmousemove="('comment',' Speed on ahead of her, lest we be tempted.');"><sup>4</sup></span> 'But you yourself said that in the case of respectable people it is well,' he protested.'
Teshuvot Maharam
A. It is an accepted custom throughout the Diaspora for small communities to hire one or two adult males whenever it is necessary to complete a minyan (quorum) for the high holidays. Therefore, if there are exactly ten adult males in the community, the other remaining members can compel the member seeking to leave either to remain in town or to hire somebody else in his stead. But, if there are eleven adult males in the community, no single member can be restrained from leaving; for he does not have to provide for the possibility of another member becoming sick or indisposed. However, if two out of the eleven want to leave, both have to share the expenses of hiring a person to complete the minyan.
Q. When nine Jews have to hire a tenth in order to complete the minyan (quorum), or when they have to hire a cantor for the holidays, do the members share equally in expenses, or do they pay in proportion to their wealth?
A. Since the members do not join a large community for the high-holyday prayers because they do not want to leave their homes, their possessions, and their investments, the forming of the local minyan is dependent upon monetary considerations, and the expenses thereof should be shared by the members in proportion to their wealth.
SOURCES: Pr. 1016; Mord. B. B. 878–9; Hag. Maim. to Tefilah, 11, 1. Cf. Agudah B. B. 15; Maharil, Responsa 107b; Israel Bruno, Responsa 163; Isserlein, Pesakim 243; Judah Minz, Responsa 7.