Which aspect of Halacha specifically governs the practice of prayer?

Halacha encompasses a comprehensive set of guidelines that govern daily Jewish life, and this includes regulations pertinent to the practice of prayer. The Halachic guidelines provide detailed instructions about how, when, and where prayers are to be conducted, as well as the appropriate intentions and attitudes one should hold during prayer.

For example, the Siddur (prayer book) contains established prayers and the manner in which they must be recited. Halachic teachings delineate various prayer obligations such as the three daily prayers, the significance of community prayer (minyan), and the proper form and times for different types of prayers. This structured approach is essential in maintaining the integrity and sanctity of the prayer experience in Judaism.

The other aspects—ethical teachings, historical context, and moral philosophies—while they may influence one's spirituality or understanding of prayer, do not specifically govern or set forth the practical and ritual aspects of how prayer is performed according to Halacha. Hence, Halachic guidelines are the primary source that dictates the practice of prayer.