Does the verse, "And you were on the brink of a pit of fire, and He saved you from it," refer to the torment of the grave, given that its apparent meaning indicates that death is the only barrier between a person and the Fire?

None of the scholars have used this verse as evidence for the punishment of the grave, nor have they interpreted the 'pit' mentioned therein as the pit of the grave. However, dying upon disbelief is one of the causes for the punishment of the grave and the Fire.

Ibn al-Jawzi, al-Tabari, and al-Razi likened the verse to the disbelievers being on the verge of destruction and torment, meaning they were about to fall into the Fire due to their disbelief before Allah guided them to Islam.