Wis 16:28

“It seems to me that, to complete the argument of the prayer, it would not be out of place after this to discuss briefly the disposition and the attitude that one who prays must have, as well as the place where one should pray and the direction he should face (if circumstances permit) and the choice of the appropriate time for praying, and topics of this kind. Disposition refers to the soul, attitude to the body. Thus Paul says … one must pray "without anger or dissension." The attitude consists in "raising pure hands," expressions that seem to me to be derived from the psalms, which say, "May the raising of my hands be like the evening sacrifice." Regarding the place, "I want therefore that people pray in every place." Regarding the orientation, the Wisdom of Solomon says, "To make it known that one must rise before the sun to give you thanks and worship you before the dawning of the light."”

“That it might be known to all, namely through this sign, that one must rise before the sun, that is, before the rising of the sun, for your blessing, supply: to be obtained, that is, to receive and gather the manna, lest after the rising of the sun it be liquefied by the heat of the sun: thus, to obtain the blessing of grace, one must rise before the sun by keeping vigil in the morning, according to that passage of Proverbs 8: "Those who watch for me in the morning will find me"; in the Psalm: "In the morning I will stand before you and I will see," etc. And at the rising of the light, that is, as soon as the light rises, or toward the east, where the light rises, to adore you, namely for the reception of the manna itself: toward the east, I say, because, as Damascene says, everything that is better must be attributed to God; whence, because the east is the nobler part of the sky, therefore one must worship toward the east, according to that passage of the Psalm: "He who ascends above the heaven of heavens toward the east." It should be noted, moreover, that in the fact that the manna melted at the rising of the sun, it was signified, according to the Gloss, that at the rising of Christ the old sacrament would cease, because "Christ is the end of the Law," Romans 10.”