Excerpted from the Handbook for Church Servers of Sergei Bulgakov:
The church service for this Sunday is devoted to the memory and glorification of the spiritual efforts of Saint Mary of Egypt, who "has cut down with the sword of abstinence the desires of your soul and the passions of your flesh. You have choked your sinful thoughts with the silence of the ascetic life, and you have watered all the wilderness with the streams of your tears, and caused the fruits of repentance to spring up for us" and "with works of Lenten fasting", "as the sun she shines revealed as a guide to all who have sinned".
In her life the Holy Church pays attention to two contrasts: on the depth of her sinful falling and on the height of her graceful rising, that it points out that true repentance wipes away the very heaviest sins, and can uplift the repenting trespasser to a high degree of spiritual perfection. The Odes of the Canon opens the parable about "the rich man and Lazarus". This parable through its imagery gives a lesson on the efforts of fasting that they, fasting physically, fasted also spiritually, that is, they helped their needy brothers and eased the portion of the suffering; but the suffering and the deprived are inspired by patience and magnanimity, by the example of Lazarus who for these virtues "was worthy of Paradise of sweetness". Inspiring those who fast with the necessity of charity, the Holy Church hymns: "The Kingdom of God is not food and drink, but righteousness and abstinence with holiness; therefore the rich shall not enter into it, but those who entrust their treasures into the hands of the needy. This is what David the prophet teaches us saying: the righteous man shows mercy all day, his delight is in the Lord, and walking in the light he will not stumble. All this was written for our admonition, that we should fast and do good, and the Lord will reward us with heavenly things instead of earthly things".
The Resurrection gospel proclaims the approaching time of the coming Passion of Christ, and the Epistle reading explains the saving actions of the offering of the Savior on the cross. With these reminders of the parable about the rich man and Lazarus and suffering, death and resurrection of the Savior, the Holy Church relates the fifth Sunday to a relationship of the coming end of the Lenten effort with the memory connected to Him.
From the Lenten Triodion:
The power of Thy Cross, O Christ, has worked wonders, for even the woman who was once a harlot chose to follow the ascetic way. Casting aside her weakness, bravely she opposed the devil; and having gained the price of victory, she intercedes for our souls.
The desires of thy soul and the passions of thy flesh thou hast cut down with the sword of abstinence; thy sinful thoughts thou hast choked with the silence of the ascetic life. With the streams of thy tears thou hast watered all the wilderness, and caused the fruits of repentance to spring up for us: therefore, O saint, we celebrate thy memory.
The wealth of my lusts has made me like the rich man who lived each day in luxury. Therefore I pray to Thee: deliver me from the fir as Thou hast delivered Lazarus, O Saviour.
I am clothed in sensual pleasures, O Saviour, like the rich man who was clothed in fine linen and in golden ornaments and raiment. But send me not into the fire as he was sent.
I am rich in the deceptive joys of this life, like the rich man who spent all his days in pleasure; but, I pray Thee, loving Lord, in Thy compassion deliver me from the fire as Thou hast saved Lazarus.
The story in full of St. Mary of Egypt is available here.