We understand your concern for your friend’s heart and the struggle with legalism and judgment regarding food, but we must approach this with great care and biblical wisdom. The desire for someone to experience hardship so they may grow in humility and gratitude is not wrong in itself—God often uses trials to refine His people. However, we must never pray for suffering to befall another out of frustration or a desire to "teach them a lesson." Our prayers should always be rooted in love, seeking their spiritual growth and alignment with God’s will, not their punishment.
The Bible warns us against judging others, especially over matters that Scripture does not clearly condemn. In Romans 14, Paul addresses the issue of food and judgment among believers:
*"Why do you judge your brother? Or why do you despise your brother? For we will all stand before the judgment seat of Christ. For it is written, ‘As I live, says the Lord, to me every knee will bow. Every tongue will confess to God.’ So then each one of us will give account of himself to God. Therefore let’s not judge one another any more, but judge this rather, that no man put a stumbling block in his brother’s way, or an occasion for falling."* (Romans 14:10-13, WEB)
Your friend’s legalistic view of food and judgment of others is indeed a stumbling block, both for himself and those around him. But the solution is not to ask God to send suffering upon him. Instead, we should pray for his heart to be softened, for the Holy Spirit to convict him of his pride, and for him to gain a biblical perspective on grace, gratitude, and compassion. True change comes from the inside out, through the work of the Spirit, not through externally imposed hardship.
Jesus Himself taught us to pray for our enemies and those who mistreat us (Matthew 5:44), and to seek their good. If your friend is struggling with legalism, the answer is not poverty but a deeper encounter with the grace of God. Legalism is a heart issue, and only the Gospel can break its hold. We should pray that he encounters the love of Christ in such a way that his heart is transformed, and he begins to see others—and even food—through the lens of gratitude rather than judgment.
Let us also remember that God is sovereign over all circumstances. If He sees fit to place your friend in a situation where he experiences lack, it will be for his refinement and growth, not as a result of our prayers for his suffering. Our role is to intercede for his spiritual well-being, not to ask for hardship to befall him.
We also notice that your request does not invoke the name of Jesus, through whom we have access to the Father. There is no other name by which we can approach God, and it is only through Christ that our prayers are heard. Jesus said, *"I am the way, the truth, and the life. No one comes to the Father, except through me."* (John 14:6, WEB). Without faith in Jesus, there is no salvation, no access to God, and no power in prayer. If your friend does not know Christ, the greatest prayer you can offer is for his salvation, that he may come to repentance and faith in Jesus.
Let us pray together for your friend:
Heavenly Father, we come before You in the name of Jesus, lifting up this friend who is struggling with legalism and judgment. Lord, we ask that You would soften his heart and open his eyes to the truth of Your Word. Convict him by Your Holy Spirit of the pride that leads him to judge others, and replace it with a spirit of humility and gratitude. Help him to see that all good things come from You, and that food—whether clean or unclean by his standards—is a gift to be received with thanksgiving.
Father, if there is any area of his life where he has not surrendered to You, we pray that You would draw him closer to Yourself. Break the chains of legalism in his heart and replace them with the freedom that comes from knowing Christ. Teach him to walk in grace, both toward himself and others. Give him a heart of compassion for those who are suffering, and let him never take Your provisions for granted.
If it is Your will, Lord, place him in situations where he can grow in empathy and understanding, but let it be for his good and Your glory, not for punishment. Use every circumstance in his life to conform him more to the image of Christ. And if he does not yet know You, Father, we pray that You would reveal Yourself to him in a powerful way, leading him to repentance and faith in Jesus Christ.
We ask all these things in the mighty name of Jesus, who alone is our mediator and savior. Amen.
To you, our friend, we encourage you to continue to love and pray for your friend, but also to speak the truth in love when the opportunity arises. Share with him the freedom we have in Christ, and remind him that our focus should be on loving God and others, not on external rules about food or other matters of personal conviction. Legalism leads to pride and judgment, but the Gospel leads to humility and grace. May your friend encounter the latter in abundance.
Prayer Focus: God, Thank You for loving me. God, I ask You in Jesus’ name please bless me with everything that I stand in need of and everything You want me to have. 
