Is it forbidden to use cement, bricks, and anything touched by fire in the grave, as is said?

The best is for the grave to be a laḥd (niche), which is dug by excavating the grave and then digging a smaller niche at its bottom, on the side facing the qiblah. This is done in firm ground, because it is what Allah chose for His Prophet. It is permissible for it to be a shaqq (trench), where the deceased is placed at the bottom of the excavation, and then covered from above with unbaked bricks (labin) or wood. It is disliked to place anything touched by fire, such as fired bricks (ājurr), cement, or iron, in the grave, except out of necessity, as the dislike is removed by necessity, and because there is no established prohibition from the Prophet regarding this.