Is it obligatory to climb the hills of al-Safa and al-Marwah during the sa'y?

Question:
Peace be upon you, Honorable Shaykh. This questioner says: It is known that it is a recommended practice (sunnah) during the sa'y for the one performing it to climb the hills of al-Safa and al-Marwah, starting with the Prophet (peace and blessings be upon him). But these days, during the Hajj and the heavy crowds, is it sufficient for the one performing sa'y to just go back and forth after reaching the end of the barrier separating the two? And is that permissible, or is it necessary to climb the hill or go around the pillar or the dome on the second floor?

Answer:
The ascent is not on the entire hill, but on the edge of the hill, on the edge of Jabal Abi Qubays, which is al-Safa, and on the edge of Jabal Qaiqizan, which is al-Marwah. It is on the edge of the hill, on a part of the hill. And this ascent is a recommended practice (sunnah), not obligatory. The obligatory part is to cover the entire distance between al-Safa and al-Marwah; that is what is obligatory: that nothing remains between al-Safa and al-Marwah that has not been covered by the sa'y.
As for climbing al-Safa and climbing al-Marwah, that is a recommended practice (sunnah). If it is possible, then it is a recommended practice (sunnah). If it is not possible, then his sa'y is valid if he covers the entire distance between al-Safa and al-Marwah. He asks about going around the pillar or the dome; there is nothing wrong with that. The important thing is that he covers the entire distance between al-Safa and al-Marwah. And if the ascent on al-Safa or al-Marwah takes place, that is a recommended practice (sunnah). Going around the pillar or whatever he goes around, it is all the same.