Ruling on one who asks for charity for someone else, then keeps it for himself because he is poor
Question

There is a poor man who asks for charity for himself, but he does it in an indirect manner, because he feels embarrassed about that, so he says: I know someone who needs charity. So people give to him, then he keeps it for himself, and by doing that he maintains his dignity in front of people. What is the ruling on that?
Praise be to Allah.Firstly:
Ruling on asking people for money
The basic principle is that it is prohibited to ask of people, unless that is in exceptional circumstances.
Al-Bukhari (1475) and Muslim (1040) narrated that ‘Abdullah ibn ‘Umar (may Allah be pleased with him) said: The Prophet (blessings and peace of Allah be upon him) said: “A man will keep on begging from people until he comes on the Day of Resurrection with not a bit of flesh on his face.”
Al-Bukhari (650), Abu Dawud (1626), an-Nasa’i (2592) and Ibn Majah (1840) narrated that ‘Abdullah ibn Mas‘ud said: The Messenger of Allah (blessings and peace of Allah be upon him) said: “Whoever begs from people when he has enough to suffice him,  will come on the Day of Resurrection with his begging like scratches or gashes on his face.” It was said: O Messenger of Allah, what is sufficient for him? He said, “Fifty dirhams, or their value in gold.”
It is not permissible to ask of people except in very few [?] circumstances, because of the report narrated by Muslim (1044) from Qabisah ibn Mukhariq al-Hilali, who said: I incurred a debt (in order to reconcile between two parties) and I came to the Messenger of Allah (blessings and peace of Allah be upon him) to ask him (for help) with it. He said: “Stay with us until the zakah comes, and we will order that something be given to you.” Then he said: “O Qabisah, asking for help is not permissible except in one of three cases: a man who has incurred a debt (in order to reconcile between two parties), for whom it is permissible to ask for help until he has paid it off, then he should refrain; a man who has been stricken by a blight that has destroyed all his crops and wealth, for whom it is permissible to ask for help until he has enough to get by – or he gets enough to meet his basic needs; and a man who is stricken by poverty and three men of wisdom among his people acknowledge that So and so has been stricken by poverty, then it becomes permissible for him to ask for help until he has enough to get by – or to meet his basic needs. Apart from these cases asking for help, O Qabisah, is haram and the one who collects it is consuming something haram.”
It says in Fatawa al-Lajnah ad-Da’imah (24/375): It is permissible to ask people for money for a needy person who does not have enough to suffice him, and is not able to earn money. He may ask people for enough to meet his need only.
As for one who is not in need, or one who is in need but is able to earn money, it is not permissible for him to ask of people, and whatever he takes from people in this case is haram for him, because of the hadith of Qabisah… End quote.
So this brother should think about whether it is permissible for him to ask of people or not.
Secondly:
One who is appointed to distribute charity and decides to take some of it for himself if he is poor
The jurists differed concerning someone who is appointed to distribute charity or zakah: does he have the right to take some of it for himself if he is poor?
Ibn Qudamah (may Allah have mercy on him) said: If he is appointed to give out charity to the needy and he is needy, or he is instructed to distribute one third of it to some people and he is one of them, or he is given money and is instructed to distribute it to whomever he wants or to give it to whomever he wants, then what is narrated from Ahmad is that it is not permissible for him to take any of it. Ahmad said: If he has in his possession money to be given to the poor and spent on charitable causes and he is in need, he should not consume any of it, because he was only instructed to distribute it. That is because the general meaning of the instructions given by the one who appointed him indicates that it should be given to others."(Al-Mughni  5/70).
Shaykh Ibn ‘Uthaymin was asked about a poor man who takes zakah from his rich friend on the grounds that he will distribute it, then he keeps it himself. What is the ruling on doing that?
He replied: This is haram for him, because it is betraying the trust. His friend gave it to him on the basis that he would act as his proxy and give it to others, but he is taking it for himself. The scholars stated that it is not permissible for a proxy to give to himself that which he has been appointed to distribute.
Based on that, what this person must do is explain to his friend that what he used to take before was spent on himself. If he pardons him, all well and good, but if he does not pardon him, then he is liable, meaning that he is liable for what he kept for himself and must give that amount as zakah on behalf of his friend."(Fatawa Arkan al-Islam  p. 447).
This applies to one who is given money to distribute without asking for that, so how about if he asks for it and pretends that it is for others?
If he is given money to distribute without asking for it, it may be that he is included in what the giver said, “Give it to the poor.” But if he asked for it and said: “There is a poor person who is in need of money,” in that case what would come to the giver’s mind is that it was for someone else, so he is not included in what he said to the giver and his taking anything of that money is a betrayal of the trust, as noted above in the words of Shaykh Ibn ‘Uthaymin (may Allah have mercy on him). Opening this door will result in a great deal of trouble and betrayal, and will lead to carelessness regarding the matter of devouring people’s wealth unlawfully.
And Allah knows best.