This is because, when he passes the Yemeni Corner, he passes it while still engaged in his circumambulation; but when he reaches the Black Stone, his circumambulation has ended before he comes fully abreast of it. Therefore, he neither touches the Black Stone nor says the takbir, because the takbir follows the touching, and at that point there is no touching. Moreover, the takbir belongs at the beginning of a circuit, not at its end.
His statement, “He touches the Stone and the Yemeni Corner each time,” refers to two well-known places. The Yemeni Corner is so called because it lies on the side facing Yemen. It and the Black Stone are also called the two Yemeni Corners. The Ka'bah has four corners: the Black Stone, the Yemeni Corner, the northern corner, and the western corner. Thus, one touches the Yemeni Corner and the Black Stone, but does not touch the northern or western corners.
One day, the Commander of the Faithful, Mu'awiyah, may Allah be pleased with him, performed circumambulation and began touching all four corners. Ibn Abbas, may Allah be pleased with them both, objected to this. Mu'awiyah said to him, “No part of the House should be neglected.” He justified this on rational grounds, but rational arguments may be unsound.
Ibn Abbas, may Allah be pleased with them both, said to him: “There has certainly been for you in the Messenger of Allah an excellent example.” The Prophet, peace and blessings be upon him, touched only the two Yemeni Corners of the House. Mu'awiyah replied, “You have spoken the truth” (1), and ceased touching the northern and western corners, because the Companions sought the truth.