Hadith: Allah Almighty says: I will declare war against one who shows hostility to a close ally of Mine. And the most beloved thing with which My slave comes nearer to Me is what I have enjoined upon him

عَنْ أَبِي هُرَيْرَة رَضِيَ اللَّهُ عَنْهُ قَالَ: قَالَ رَسُول اللَّهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ:
«إنَّ اللَّهَ تَعَالَى قَالَ: مَنْ عَادَى لِي وَلِيًّا فَقْد آذَنْتُهُ بِالحَرْبِ، وَمَا تَقَرَّبَ إلَيَّ عَبْدِي بِشَيْءٍ أَحَبَّ إلَيَّ مِمَّا افْتَرَضْتُ عَلَيْهِ، وما يَزَالُ عَبْدِي يَتَقَرَّبُ إلَيَّ بِالنَّوَافِلِ حَتَّى أُحِبَّهُ، فَإِذَا أَحْبَبْتُهُ كُنْتُ سَمْعَهُ الَّذِي يَسْمَعُ بِهِ، وَبَصَرَهُ الَّذِي يُبْصِرُ بِهِ، وَيَدَهُ الَّتِي يَبْطِشُ بِهَا، وَرِجْلَهُ الَّتِي يَمْشِي بِهَا، وَإِنْ سَأَلَنِي لَأُعْطِيَنَّهُ، وَلَئِنْ اسْتَعَاذَنِي لَأُعِيذَنَّهُ».
[صحيح] - [رواه البخاري] - [الأربعون النووية: 38]

Abu Hurayrah (may Allah be pleased with him) reported: The Messenger of Allah (ﷺ) said:
"Allah Almighty says: I will declare war against one who shows hostility to a close ally of Mine. And the most beloved thing with which My slave comes nearer to Me is what I have enjoined upon him; and My slave keeps on coming closer to Me through performing supererogatory acts of worship till I love him. When I love him, I become his hearing with which he hears, his sight with which he sees, his hand with which he seizes, and his leg with which he walks; and if he asks (something) from Me, I will surely give it to him, and if he asks My Protection (refuge), I will surely protect him."
[Authentic hadith] - [Narrated by Bukhari] - [الأربعون النووية - 38]

Explanation

The Prophet (ﷺ) informed, in the Divine Hadīth, that Allah Almighty said: Whoever harms a close ally of Mine, angers him, or shows him enmity, I have declared war against him and announced My hostility toward him. "Waliyy" is: the pious believer. The servant's share of Allah's closeness is in proportion to his level of faith and piety. A Muslim does not draw nearer to his Lord with anything more beloved to Him than what He has made obligatory upon him—performing the acts of obedience and avoiding the prohibitions. Then the Muslim continues to draw closer to his Lord with voluntary deeds alongside the obligatory ones until he attains Allah's love. When Allah loves him, Allah grants him guidance and success in these four faculties: He rightly guides him in his hearing; thus, he hears nothing but what pleases Allah. He rightly guides his sight; thus, he looks at nothing except what Allah loves to look at and what pleases Him. He rightly guides his hands; thus, he does nothing with his hand except what pleases Allah. He rightly guides his feet; thus, he walks to nothing except what pleases Allah and pursues only what is good. Along with all this, if he asks Allah for something, He grants him his request, and his supplication will be answered; and if he seeks refuge with Allah and resorts to Him seeking protection, Allah Almighty will grant him refuge and protection against what he fears.

Benefits from the Hadith

1. This Hadīth is part of what the Prophet (may Allah's peace and blessings be upon him) narrates from his Lord, and it is called a Qudsi or Divine Hadīth. Its wording and meaning are from Allah; however, it does not have the unique characteristics of the Qur'an that include reciting it as a form of worship, getting purified for it, presenting it as a challenge, its miraculousness, etc.
2. It is prohibited to harm the pious worshippers of Allah, but loving them and acknowledging their merits are encouraged.
3. It is commanded to show enmity towards the enemies of Allah and it is prohibited to take them as allies.
4. Whoever claims to be a pious worshipper of Allah without following His Shariah is a liar in his claim.
5. Being a pious worshipper of Allah can be attained by carrying out religious duties and refraining from prohibitions.
6. Among the means that lead one to attain the love of Allah and to have his supplication answered is performing supererogatory deeds after carrying out the duties and refraining from the prohibitions.
7. Indicating the honor and high status of the pious worshippers.