How sound is the narration: "Indeed, the dead are tried in their graves for seven days, and they (the Companions) used to find it desirable to offer food on their behalf during those days," and can it be used as evidence for the permissibility of serving food in the house of mourning?

The narration regarding the trial of the deceased for seven days in their graves and feeding the poor on their behalf during those days is weak and disconnected. Matters of the unseen should only be derived from scriptural texts or authentic narrations from the Companions. Furthermore, it contradicts what is established in authentic texts, which state that the trial of the believer in the grave occurs only once, with the questioning by the two angels.

The narration from Mujahid specifying the days of the grave's trial for the believer has no basis in the authenticated books of Hadith (definition), and it does not mention feeding.

What came from Ubaid ibn Umair appears to have an authentic chain of narration, but it does not include feeding on behalf of the deceased. The mention of charity on his behalf was an addition by Ibn Juraij. As for the claim that the disbeliever is not questioned in his grave, the verifying imams have refuted it, based on the Qur'an and Sunnah (definition), which indicate that the questioning applies to both the disbeliever and the Muslim.

What is authentically established in the Prophetic Sunnah and the narrations of the Companions is the preparation of food for the family of the deceased due to their preoccupation, and not feeding or giving charity at a specific time after burial, nor the family of the deceased preparing food for people.