his mount, facing whichever direction it was heading, and he would not do that in the obligatory prayers.” [Al-Bukhārī 1093; Muslim 701]
The well-known position in the Hanbalī school is that the worshipper must face the qiblah for the takbīrat al-iḥrām, either by turning his animal or by turning himself. The proof is the ḥadīth of Anas reported by Abū Dāwūd.
Another report from Imām Aḥmad, however, holds that facing the qiblah is not required, even for the takbīrat al-iḥrām. This is also the view of Abū Ḥanīfah and Mālik, for the authentic ḥadīths speak in unrestricted terms. As for the ḥadīth of Anas, it is interpreted as merely recommended.
Ibn al-Qayyim commented, “The ḥadīth of Anas is questionable, for everyone who described the Prophet’s ﷺ prayer on his mount stated plainly that he would pray on it whichever way it was facing, without excluding the takbīrat al-iḥrām or any other part of the prayer.”
Fourth: According to the school of Imām Aḥmad, it is permissible to pray on a riding animal while travelling, even on a short journey. Al-Muntahā and its commentary state, “It is permissible to perform a voluntary prayer on a mount while facing other than the qiblah, and while travelling even if the journey is brief; this is the explicit statement of Imām Aḥmad.”