Shaykh Ṣāliḥ al-Fawzān explains that while questioning in the grave is certain, the language used is unknown, as it was not specified by the Prophet ﷺ.
In which language will the dead be questioned in the grave?
Allah ﷻ knows best. We believe he will be questioned and Allāh ﷻ knows best [in which] language. The Prophet ﷺ did not explain that to us.
