Moreover, specifying the Quran by the sunnah is weaker than specifying the Quran by the Quran.

However, we say: the sunnah may come from the Messenger, peace and blessings be upon him, by Allah’s explicit command, or by His tacit approval—whereby Allah approves His Prophet in what he says or does. Hence, when the Messenger, peace and blessings be upon him, does something that Allah does not approve of, He makes it clear, as Allah Most High said to him:

“May Allah pardon you! Why did you grant them leave before it became clear to you who were truthful and you came to know the liars?” [al-Tawbah]

And He, Most High, said:

“O Prophet, why do you prohibit what Allah has made lawful for you?” [al-Tahrim: 1]

And He, Glorified and Exalted is He, said:

“And when you said to him upon whom Allah had bestowed favor and you had bestowed favor, ‘Keep your wife and fear Allah,’ while concealing within yourself what Allah was to disclose, and fearing the people, though Allah had more right that you should fear Him.” [al-Ahzab: 37]

Therefore, we say that the Messenger’s action, peace and blessings be upon him, of not facing the qiblah when offering voluntary prayers while travelling was by Allah’s tacit approval, because He approved it. Thus, what the sunnah establishes is exactly like what the Quran establishes in being authoritative evidence.

If it is asked: May a traveller offer an obligatory prayer while riding and moving, without facing the qiblah?

The answer is: No—except when facing the qiblah is impossible.

If it is asked: If a traveller has stopped at a place, may he offer voluntary prayers facing a direction other than the qiblah?

The answer is: No, because the specification of a general text is restricted solely to the particular case in which that specification occurred.