What is the ruling on an Imam who recites during prayer the verse: "When they were in the cave, he said to his companion, 'Do not grieve'," and then quietly invokes Allah's pleasure upon Abu Bakr? Is this permissible?

The majority of scholars are of the opinion that it is recommended to ask [Allah] at a verse of mercy, to seek refuge [in Allah] at a verse of punishment, and to glorify [Allah] at a verse of glorification during supererogatory prayers. The Shafi'is recommended it also for obligatory prayers, while the Hanbalis permitted it without recommending it.

As for sending blessings upon the Prophet, peace and blessings be upon him, when passing by a verse containing his name, the jurists differed. The Shafi'is recommended it in both obligatory and supererogatory prayers, and the Hanbalis in supererogatory prayers only. Some Malikis permitted it, while the Hanafis stated that it invalidates the prayer if done as a response.

Regarding seeking Allah's pleasure for the Companions when they are mentioned, it appears permissible as it is a supplication. However, refraining from it might be better due to the absence of a textual proof for it, and to avoid the disagreement of those who invalidate the prayer by it if it is done as a response, such as the view of the Hanafis.