Say, ‘I have faith in Allah,’ and then remain steadfas

Sufyan ibn Abdullah reported: I said, “O Messenger of Allah, tell me of a saying in Islam after which I will not need to ask anyone after you.” The Messenger of Allah, peace and blessings be upon him, said:‏‏

Say, ‘I have faith in Allah,’ and then remain steadfast.

Source: Ṣaḥīḥ Muslim 38, Grade: Sahih