Commentary for Rosh Hashanah 57:3
הכא בשליח ציבור עסקינן דדעתיה אכוליה עלמא
Come and hear: 'If the hearer put his mind to it but not the performer, or if the performer put his mind to it but not the hearer, he did not perform his religious duty; [he does not do so] until both the hearer and the performer put their mind to it'. Here he mentions the performer in the same breath with the hearer, [to indicate that] just as the hearer hears for himself, so the performer performs for himself, and [in such a case] he states that 'he did not perform his religious duty'?<span class="x" onmousemove="('comment',' [This is difficult, v. Marginal Glosses, Bezaleel Ronsburg. Read with MS.M.: 'and it states (in such a case, i.e., where the performer performs for himself provided the hearer puts his mind to it) he performed his duty.]');"><sup>2</sup></span>