Reference for Eruvin 67:3
איתיביה נתכוון לשבות ברה"ר והניח עירובו בכותל למטה מעשרה טפחים עירובו עירוב למעלה מי' טפחים אין עירובו עירוב נתכוון לשבות בראש השובך או בראש המגדל למעלה מי' טפחים עירובו עירוב למטה מי' טפחים אין עירובו עירוב
lower than ten handbreadths [from the ground], his 'erub is effective,<span class="x" onmousemove="('comment',' Since it is possible to carry it from the wall to the 'abode' in small stages of less than four cubits. Such a mode of carrying is forbidden on the Sabbath proper by a Rabbinical measure only; and, as the twilight of the Sabbath eve is regarded as Sabbath proper also by a Rabbinical measure only and as one Rabbinical measure cannot he imposed upon another, the carrying in small stages has not been forbidden at twilight when the acquisition of the 'abode' takes place.');"><sup>6</sup></span> [but if he deposited it] above [a height of] ten handbreadths [from the ground]<span class="x" onmousemove="('comment',' So that the erub rested in a private domain.');"><sup>7</sup></span> his 'erub is ineffective.<span class="x" onmousemove="('comment',' Since it is forbidden even at twilight to convey from a private domain (v. previous note) into a public domain (where the man would be standing when taking down the 'erub from the wall) .');"><sup>8</sup></span> If he intended to make his abode on the top of a dove-cote, or on the top of a turret, his 'erub i valid [if it lay<span class="x" onmousemove="('comment',' In the dove-cote or turret.');"><sup>9</sup></span>