What is the ruling on the muezzin's call to prayer if he is not in a state of ritual purity (wudu') and is not facing the Qibla? And is it authentically reported that the Prophet (peace be upon him) would turn his face to the right when saying "Hayya 'ala al-Salah (come to prayer)" and to the left when saying "Hayya 'ala al-Falah (come to prosperity)"?

It is preferable for the muezzin to be in a state of ritual purity and facing the qibla when making the adhan. It is disliked for him to make the adhan while in a state of minor ritual impurity (muhdith), but his adhan is valid in both cases. If he turns his back to the qibla, his adhan is also valid, even though he has abandoned the preferred action. There is no evidence from the Prophet, peace be upon him, indicating the legitimacy of turning to the right for "Hayya 'alas-Salah" (come to prayer) and to the left for "Hayya 'alal-Falah" (come to success), but this has been authentically reported from some Companions. Turning during the "Hayya 'ala" phrases in the adhan is recommended to ensure the call reaches those invited. However, regarding the iqama, there is a difference of opinion among jurists. The muezzin should not turn if he uses a loudspeaker.