Musar for Eruvin 191:1
ואיבעית אימא דכ"ע לצאת לא בעי כוונה והכא לעבור משום בל תוסיף קמיפלגי דתנא קמא סבר לעבור משום בל תוסיף לא בעי כוונה ורבן גמליאל סבר לעבור משום בל תוסיף בעי כוונה
And if you prefer I might reply that all agree that the discharge of the duty of a commandment requires no intention, but here it is the question of transgressing against the injunction of Thou shall not add,<span class="x" onmousemove="('comment',' All this word which I command you . . thou shalt not add thereto (Deut. XIII, 1) .');"><sup>1</sup></span> that is at issue between them; the first Tanna holding that in order to commit a transgression against the injunction of Thou shall not add<span class="x" onmousemove="('comment',' All this word which I command you . . thou shalt not add thereto (Deut. XIII, 1) .');"><sup>1</sup></span> no intention<span class="x" onmousemove="('comment',' To perform the commandments.');"><sup>2</sup></span> is necessary while R'Gamaliel holds that in order to commit a transgression against the injunction of 'Thou shalt not add', intention is necessary.<span class="x" onmousemove="('comment',' V. supra p. 662, n. 12.');"><sup>3</sup></span>