In the Asclepius (chapter XLI), also called the Perfect Discourse, Hermes Trismegistus and his students Asclepius and Tat begin praying to God.  After scolding Asclepius for suggesting that they add incense to their prayer, Hermes Trismegistus proceed to show his students an example of a true prayer of gratitude.  This prayer was first discussed in this 2018 post, and bears many similarities to the Prayer of Thanksgiving as preserved in the Nag Hammadi texts, upon which the latter may have been originally based.

This text specifies that one should face the a specific direction when praying to God, one of the four cardinal directions where the Sun is closest.  Thus, one faces east at sunrise, south at noon, and so forth.

We thank you, supreme and most high God, by whose grace alone we have attained the light of your knowledge; holy Name that must be honored, the one Name by which our ancestral faith blesses God alone, we thank you who deign to grant to all a father’s fidelity, reverence, and love, along with any power that is sweeter, by giving us the gift of consciousness, reason, and understanding:
consciousness, that we may know you;
reason, by which we may seek you in our dim suppositions;
knowledge, by which we may rejoice in knowing you.

And we who are saved by your power do indeed rejoice because you have shown yourself to us wholly.  We rejoice that you have deigned to make us gods for eternity even while we depend on the body.  For this is mankind’s only means of giving thanks: knowledge of your majesty.

We have known you, the vast light perceived only by reason.
We have understood you, true life of life, the womb pregnant with all coming-to-be.
We have known you, who persist eternally by conceiving all coming-to-be in its perfect fullness.

Worshiping with this entire prayer the good of your goodness, we ask only this: that you wish us to persist in the love of your knowledge and that we never be cut off from such a life as this.

The prayer concludes with a direction to eat a vegetarian meal:

With such hopes, we turn to a pure meal that includes no living thing.

In accordance with this last statement, this prayer may be used as a type of grace prayer before meals.