When is the supplication, "O Allah, place light in my heart, and light in my hearing, and light in my tongue, and light in my sight, and light in my right hand, and light in my left hand, and light above me, and light beneath me, and light in front of me, and light behind me," to be recited?

This supplication was mentioned in the context of the hadith about Ibn Abbas (may Allah be pleased with him) sleeping at the Prophet's (peace be upon him) house. It was narrated by Al-Bukhari and Muslim within the context of the Prophet's (peace be upon him) night prayer, and that he used to recite this supplication in his prayer or in his prostration.

There is another narration in Muslim that mentions the supplication when going out for the Fajr prayer, but this narration is questionable in terms of its chain of transmission. Some scholars have deemed it weak due to its frequent contradiction of the narrations of reliable and accurate memorizers of hadith, and because its narrator, Habib bin Abi Thabit, was known for extensive tadlis (concealing defects in the chain of narration).

The more probable narration is the one that mentions the supplication during the night prayer, because the story is a single event and not multiple ones.