Reflection: At the announcement of her departure, the Mother of God "desired the life on high" and was glad to pass over to the "gladness of heaven". Fasting helps us to decrease passionate drives and carnal desires so we can desire the eternal.
Practice: Identify a "temporal desire" (a want, not a need) and offer it up to God, asking Him to replace it with a hunger for His Kingdom.
Menaion, August 15, AT LITTLE VESPERS On “Lord, I have cried…”, “The assembly of the angels rejoiceth in the immortal repose of the Mother of God; and she, departing for the eternal mansions, is glad and passeth over to the gladness of heaven, to divine joy and everlasting delight.
Desiring the life on high, thou didst abandon this one, O Theotokos, O Maiden, flower of virginity, who gavest birth to Christ, the Life of all. And the assembly of the angels stood by with reverence at thine honored burial, O Bride of God.
The air is sanctified by thy parting burial hymns; and in thine ascent, O Mother of God Who lovest mankind, is an awesome miracle wrought, O Theotokos who knewest not man. Wherefore, we, the faithful, faithfully do thee homage, O Theotokos who knewest not wedlock.”
The Orthodox Faith - Volume IV - Spirituality - Prayer, Fasting, and Almsgiving - Fasting - Orthodox Church in America: Saint Isaac of Syria says, “Meager food at the table of the pure cleanses the soul of those who partake from all passion ... for the work of fasting and vigil is the beginning of every effort against sin and lust ... almost all passionate drives decrease through fasting.”
For the holy fathers taught us to be killers of passions and not killers of the body. Partake of everything that is permissible with thanksgiving, to the glory of God and to avoid boastful arrogance; but refrain from every excess (The Monks Callistus and Ignatius, 14th c., Directions to Hesychasts).