What is the ruling on asking God for a sign to confirm the correctness of a specific action?

The fundamental principle for determining right and wrong is the Sharia. However, in cases of ambiguity, particularly concerning matters of madhhabs (schools of thought), it is permissible to ask Allah for a sign to distinguish right from wrong, as did the young man of the Ditch (Ghulām al-Ukhdūd), Abū al-Muẓaffar al-Samʿānī, and Ibn Nāṣir al-Salāmī. It is also recommended to perform Istikhara (prayer for guidance) in all matters when in doubt.