The benefits of the saying of Allah the Exalted: ((So they turned to one another, questioning. One of them said: "Indeed, I had a companion..."))

Then He said, Mighty and Majestic:
It is derived from these verses the perfect joy of the people of Paradise, and that they converse and ask one another about what happened in this world. Speaking about what happened to a person in the past brings pleasure and comfort to the soul. Have you not seen how, when you talk about your childhood, you find pleasure and comfort in it, and the time passes by without you noticing? They ask one another how things happened to us in this world, and how we reached this blessing, and other such pleasant and engaging conversations. For this reason, he said:
Among its benefits is the perfect etiquette of the people of Paradise, in that when they converse, they turn to one another, as He said: This is part of perfect etiquette: to turn toward the person you are speaking with. This is in contrast to those who have poor etiquette; you find that when conversing, he asks, "How are you, so-and-so?" while you are on his right, yet he turns away from you while asking about your condition. No matter what the situation is, it is poor etiquette. For example, if you are looking to the left because you are occupied with an important matter, such as watching a small child whom you fear might fall into a well or something similar, we say: do not converse with him while turning away from him. Once you are done with that looking, turn toward him.
Does it follow from this that it is poor etiquette to greet a person from behind? Sometimes a person is standing with a group around him, and they are all greeting him in front of him, but then someone comes from behind to greet him. You are between two options: either you turn toward him and thus turn your back to the others, or you remain facing the others and greet him while having your back to him.
The student: Should I turn toward him?

The Shaykh : No, no, I do not turn toward him. He has no right to greet me from behind while the people are in front of me.
The student: ...

The Shaykh : No, absolutely not. I say: if you want to greet, go with the people. Perhaps that is his intention... to greet and then leave. I believe this is poor etiquette, as long as all the people are facing the person. How can you greet him from behind? You want to interrupt his conversation with them just so he can greet you. If the greeting is known, even in buying bread... let it be so in greeting in any case. The fact that they turn to one another indicates that when a person wants to converse with another, he should be facing him. To converse with him from behind is not part of etiquette.
Among the benefits of the noble verse is the permissibility of speaking about the blessings of Allah in principle, and otherwise, speaking about them is among the required matters: Because this man spoke about what Allah had bestowed upon him of guidance, even though he had a companion who wanted to mislead him. And among the benefits of the noble verse is the permissibility of backbiting the person who calls to misguidance. From where is this derived? From his saying: And there is no doubt that this caller is a companion who calls to disbelief. It is permissible to backbite the caller to misguidance and disbelief for the great benefit in this world, which is warning people against him so that they do not fall into his trap.
The student: If he did not name him...?
The Shaykh : It will become known about him, even if he did not name him. If it is known specifically, there is no difference. And this question is out of place, O Khalid. All right.
There is also among the benefits that the callers to misguidance bring forth doubts that cause people to go astray. Because this caller to misguidance says: He confuses the matter and says: How can one be resurrected who was dust and bones, in order to be rewarded? And there is no doubt that such a doubt deceives the general public.
All right, so branching from this benefit is that one must be cautious of the likening of the people of misguidance, and not let their doubts enter the heart of a person. Ibn al-Qayyim mentioned from Shaykh al-Islam (may Allah have mercy on him) that he said: "Make your heart like a clear glass or a clear bottle, and do not make it like a sponge that absorbs everything that comes to it." The clear glass sees things through it clearly, but nothing enters it. If you put it in the middle of water, nothing enters it. But the sponge absorbs and accepts everything that comes to it. If even one drop falls on it, it swells from it. So a person must not absorb doubts, and his heart should be clear and pure, with nothing of these things entering it.
If someone says: I may not be able to control this matter. What is my position if a person presents me with one of the doubts? The answer to that is that we say: the presentation of a doubt by a devil of mankind is like the presentation of a doubt by a devil of the jinn. And the Prophet (peace and blessings be upon him) commanded that when doubts enter the heart of a person, he should stop them and seek refuge in Allah from the accursed Shaytan. And on this basis, the remedy is that I say: I seek refuge in Allah from the accursed Shaytan, and I get up from the place. I do not stay with them in argument, and I have no knowledge with which to refute the doubt. Rather, I get up from the gathering. As for staying while I have no knowledge with which to refute his doubts, it may affect me. So we say: get up. And your getting up from this place where you receive the doubts is the turning away or stopping that the Prophet (peace and blessings be upon him) commanded for whoever has something of the doubts enter his heart.
Among the benefits of the verses is that the most hostile enemy to a person may be the one who is his companion, as He said: And branching from this benefit is being cautious of companions, and not throwing affection and secrets to them until we know their condition. Because many people are gentle with you and walk with you, not in order to benefit from you, nor in order for you to benefit from them, but in order to see what you have, and then expose you, either in their own mind or to others. The important thing is that not every companion of a person is an advisor to him, as evidenced by this: So beware of companions. Do not rely on them until you know the truth of their advice and affection. And at that time, a person is civil by nature. A person must have a companion and a friend to whom he complains of his affairs, confides his secrets, and consults about his affairs. This is necessary. But beware, do not rely on a person unless you know his truthfulness.