Is 'Umar ibn 'Abd al-'Aziz's agreement with al-Walid to include the chamber in the mosque a proof for the grave-worshippers?

Question:
He says: Honorable Shaykh, may Allah grant you success, is there a proof for these grave-worshippers in 'Umar ibn 'Abd al-'Aziz (may Allah have mercy on him) agreeing with al-Walid to include the chamber in the mosque, and also in his keeping it there during his caliphate?

Answer:
No, the mosque was not built on the chamber so that they could use it as a proof. The chamber was built for residence; it was not built because it was a mosque. It was built for residence, and the mosque was built for prayer. It was adjacent to the mosque. Al-Walid erred in including it in the mosque, and he contradicted the caliphs before him, who used to expand the mosque to the west and to the north, and leave the eastern side. He erred in this. And 'Umar was merely an executor; he was a governor for al-Walid, so he had no choice but to carry out his orders. There is no proof in this.