In The Name of Allaah, The Most Merciful, The Bestower of Mercy.
Anas Bin Maalik [radiyallaahu anhu] said, “A man went past the Prophet [sallal laahu alayhi wasallam] whilst there were people with him [i.e. with the Prophet]; so [another] man who was with the Prophet said, ‘Indeed, I love this one [i.e. the one who went past] for the sake of Allaah’. The Prophet [sallal laahu alayhi wasallam] said, ‘Have you made that known to him?’ He said, ‘No’. The Prophet said, ‘Get up and make that known to him’. He went to him and made that known’, so he [i.e. the other man] said, ‘May the one for whose sake you love me also love you’. Then he returned to the Prophet [sallal laahu alayhi wasallam] and informed him regarding what the man said, so the Prophet [sallal laahu alayhi wasallam] said, ‘You will be with the one you love and will receive what you hope for [i.e. reward]’”.
Shaikh Zayd Bin Haadi [rahimahullaah] said:
In this this hadeeth, there is a clarification [regarding the fact that] the Prophet [sallal laahu alayhi wasallam] used to sit with his companions to speak to them and make known to them that which they were in need of.
In this hadeeth, there is [proof regarding the fact that] it is obligated on the believers to love one another and establish that which is necessary to establish this love. The love legislated in the Sharee’ah is an act of worship of the heart, and there are deeds that would necessitate its existence, such as being good to the person you love, visiting the sick, following the Janaazah, giving sincere advice, enjoining good and forbidding evil, and helping him in that which is good. All these deeds and others are from that which necessitates the presence of that love that is legislated in the Sharee’ah, whose meaning is that a believing man loves another believing brother for the sake of Allaah, because he is steadfast upon Allaah’s Sharee’ah.
In this hadeeth, there is [proof to show that] it is legislated to inform someone you love for the sake of Allaah about it, saying: “Indeed, I love you for the sake of Allaah”, so that a bond is created between you and him, and he knows that he has brothers in Eemaan who love him and wish good for him just as they love good for themselves.
In this hadeeth, [there is proof to established the fact that] reward is given based on the deed, because whoever loves another person for the sake of Allaah, Allaah also will love him. And whoever Allaah loves, Allaah will honour him due to being pleased with him and enter him into Jannah- a Jannah whose width is that of the heavens and the earth.
And in this hadeeth, there is evidence to show that those who love one another for the sake of Allaah- truthful about it and visiting one another- have a lofty status in the sight of Allaah, just as it has been established in a sound hadeeth reported by Imaam Muslim [rahimahullaah] from Abu Hurairah [radiyallaahu-anhu] who said, “The Messenger of Allaah [sallal laahu alayhi wasallam] said that Allaah said, ‘Indeed Allaah will say on the day of Judgement, ‘Where are those who loved one another for my sake; I will provide them with a shade on this day in which there will be no shade except my shade [Ref A] [i.e. Allaah will provide them with a shade from His Throne]. [Source: At-taleeqaatul Maleehah Alaa Silsilah Al-Ahaadeeth As-Saheehah vol 1.pages 139-140. Slightly paraphrased]
Questioner asked Shaikh Albaani [rahimahullaah]: Is it obligated on a person who loves another person to say to him, “I love you for the sake of Allaah?”
Shaikh Albaani [rahimahullaah] replied: Yes, but love for the sake of Allaah has a high value and those who give [what it necessitates] are very few!! Do you know its value? Is there anyone who knows its value? Whoever knows, then let him give us an answer?
A person in the gathering replied to the Shaikh [rahimahullaah]: The Messenger [sallal laahu alayhi wasallam] said: There are seven people whom Allaah will shade with His shade [i.e. the shade of Allaah’s Throne] …and amongst them are two men who love each other for the sake of Allaah – they meet each other and depart on that basis.
The Shaikh [rahimahullaah] replied: This statement is sound within [its context], but it is not an answer to the question. It is a close definition of ‘love for the sake of Allaah’ but not a comprehensive definition. I do not mean the reward in the Aakhirah, [rather] my question is, ‘’What is the valuable thing that must be given by a person who loves another person for the sake of Allaah? The intent behind my question is what is the deed that would show -as a proof- that love for the sake of Allaah [exist] between two people who [claim] love for each other for the sake of Allaah; because it maybe be that two people love each other, but their love is based on [admiration of each other’s characteristics or traits]. Therefore, what is the proof of real love [for the sake of Allaah]?’’
A second person replied to the Shaikh [rahimahullaah]: ‘’To love for a person what you love for yourself.’’ The Shaikh [rahimahullaah] said, ‘’This is one of the qualities of loving for the sake of Allaah.’’
A third person said to the Shaikh [rahimahullaah]: The answer might be found in the hadeeth: There are three things that when found in a person, he will taste the sweetness of Eemaan….and one of those things is that one loves a person for nothing else other than for the sake of Allaah. Shaikh said: This is not the answer, rather this is [one of the] effects of loving for the sake of Allaah – the sweetness found in one’s heart.
A fourth person said to the Shaikh [rahimahullaah]: Allaah [The Most High] said:
إِنَّ ٱلۡإِنسَـٰنَ لَفِى خُسۡرٍ
إِلَّا ٱلَّذِينَ ءَامَنُواْ وَعَمِلُواْ ٱلصَّـٰلِحَـٰتِ وَتَوَاصَوۡاْ بِٱلۡحَقِّ وَتَوَاصَوۡاْ بِٱلصَّبۡرِ
By Al-‘Asr (the time). Verily! Man is in loss; Except those who believe [in Islamic Monotheism] and do righteous good deeds and recommend one another to the truth [i.e. order one another to perform all kinds of good deeds which Allaah has ordained and abstain from all kinds of sins and evil deeds which Allah has forbidden], and recommend one another to patience [for the sufferings, harms, and injuries which one may encounter in Allaah’s Cause].
The Shaikh [rahimahullaah] replied: Well done! This is the answer. If I really love you for the sake of Allaah, I will give you advice and likewise you’ll do the same for me. This act of giving advice is very rare amongst those who claim that they love each other for the sake of Allaah. It may be that there is some sincerity in their love, but it is not complete. Therefore, every one of us should safeguard the other, and -in this case- the valuable thing to be given due to loving one another for the sake of Allaah is that everyone sincerely advises one another, by enjoining good and forbidding evil – always and forever. [Ref 1] And it has been reported that it was from the practice of the Sahaabah-amongst themselves- that when parting company from each other after meeting, one of them would recite Surah Asr to the other [Ref 2]. [الحاوي من فتاوي الألباني – page 165]
English here: When two men among the Sahaabah of the Prophet [sallal-laahu-alayhi-wasallam] met, they would not depart until one of them recited to the other: “By al‑‘Asr (the time). Verily, man is in loss”[Surah al-‘Asr], and thereafter, one would give salaam to the other. Shaikh Albaani [rahimahullaah] said in As-Saheehah Number 2648, page 308: The chain of this narration is authentic.
English text here: Then on page 309, the Shaikh [rahimahullaah] said: Finally, we take and benefit from this that the Sahaabah used hold onto this practice- the recitation of Surah Al-Asr [i.e. when two of them were about to depart from each other after meeting], because we believe that they are far removed from innovating an act of worship into the religion through which a person seeks to get close to Allaah, so they must have adhered to this practice due to what they were acquainted with from the Prophet [sallal-laahu-alayhi-wasalam]- either based on a statement of his, action or tacit approval. [Excerpt: paraphrased]
[Ref A: see Shaikh Rabee’s risaalah tiltled: القول الواضح المبين في المراد بظل الله الذي وعد به المؤمنين العاملين ]