What is meant by teaching the dying person "Lā ilāha illā Allāh" (There is no god but Allah) in the prophetic tradition: "Teach your dying ones: There is no god but Allah"?

Instructing the dying person (talqin al-mayyit) means reminding the one on their deathbed of the words "La ilaha illa Allah" (There is no god but Allah), so that their life may conclude with it, based on the hadiths regarding the virtue of whoever's last words are these. One should not overdo the instruction if the dying person has already uttered it and said nothing thereafter, for fear that they might become annoyed or say something inappropriate.

It is also permissible to instruct a disbeliever, based on what the Prophet, peace and blessings be upon him, did with his uncle Abu Talib and the Jewish boy.

A strong dying person or a disbeliever is commanded to say "La ilaha illa Allah." As for a weak Muslim, Allah should be mentioned in their presence without commanding them.

The instruction should be with "La ilaha illa Allah" only, as it is the key to Islam. However, if one says "La ilaha illa Allah Muhammad Rasool Allah" (There is no god but Allah, Muhammad is the Messenger of Allah), there is no objection to it being their last words.