Facing (Kiblah) Al Ka'ba, the Direction of Prayer

2.          to turn one's face and whole body towards the ka'aba, the holy house at makkah, intending by heart to perform the prayer which he wants to fulfill, whether it is an obligatory prayer pr a supererogatory prayer, the worshipper in all cases, should not pronounce his intention openly, because neither the prophet nor his companions used to utter the intention for prayer, thus , pronouncing the intention for prayer in audible voice is a heresy and  an illicit action, whether the individual be an imam or performs his prayer curtain for his prayer. directing the face towards the qibla (the ka'aba at makkah) is an imperative condition for every prayer. however, there are few exceptions for this rule explained in authoritative books for whom wish to refer.