What to Do If You Find Money on the Ground
Question

My question is: What is the ruling on finding money on the street? Is one allowed to keep it?
Praise be to Allah.What is al-luqatah?
This question has to do with al-luqatah, which is one of the categories of Islamic jurisprudence or fiqh. 
Al-luqatah is property that has gone missing from its owner. This pure religion teaches that property is to be protected and preserved, and that the property of the Muslim is sacred and is to be protected. This includes al-luqatah or lost property.
Types of lost property
If property goes missing from its owner, it has to be one of the following three scenarios:

The first scenario: it is something to which most people would not attach much value , such as a whip, or a loaf of bread, or some fruit, or a stick. In these cases, the person who finds the property may keep it and use it without having to announce it, because of the report narrated by Jabir, who said: “The Messenger of Allah (peace and blessings of Allah be upon him) made exceptions in the case of a stick or a whip or a rope that a man picks up.” (Reported by Abu Dawud)
The second scenario: (animals) that are unlikely to be harmed by small predators, either because of their size, such as camels, horses, cattle and mules, or because they can fly, like birds, or because they move swiftly, like gazelles, or because they can defend themselves with their fangs, like leopards. This is the category which it is haram to keep. These things do not become the property of the finder after he announces it for a year , because when the Prophet (peace and blessings of Allah be upon him) was asked about a lost camel, he said: “What has it got to do with you? It has its water, it can walk to find water and it can eat trees until its owner finds it.” (Agreed upon).

‘Umar said, “Whoever takes a lost animal is misguided ” i.e., he is a sinner. The Prophet (peace and blessings of Allah be upon him) ruled in this hadith that the lost animal should not be taken, it should be left to find its own water and to eat from the trees until its owner comes across it.
This also applies to large implements, such as big pans, wood, iron and anything that can be left alone without getting damaged. Such things can hardly be lost and cannot move from where they are, so it is haram to take them just as it is haram to take lost large animals, and in fact it may be more haram to do so.

The third scenario: any other kind of lost property, such as money , luggage, and any animals that need to be protected from small predators, such as sheep, young camels and calves. If the one who finds them can trust himself not to harm or damage these things, then it is permissible for him to pick them up. 

Types of lost money, luggage, and animals
These things are of three types:

The first type: animals that are eaten, such as young camels, sheep, chickens, the one who finds these must do what is in the best interests of the owner, which may be one of three things:


He can eat it, in which case he owes the price of the animal straight away.
He may sell it and keep the price of it to give to the owner once he has claimed it by describing the animal.

He may keep it and spend on it from his own wealth, but he does not own it, and he can claim back what he has spent on it if the owner comes and claims the animal back, because when the Prophet (peace and blessings of Allah be upon him) was asked about the sheep, he said: “Take it, because either it is for you, or your brother, or the wolf.” (Agreed upon)
The meaning is that the sheep is weak and is vulnerable to attack, so either you take it, or your brother takes it, or the wolf will eat it.
Ibn al-Qayyim said in his discussion of the hadith: 
“This includes permission to take lost sheep, and if the owner of the sheep does not come to claim it, then it belongs to the one who found it. Then he has the choice to eat it immediately, and then he will owe the price of it, or he can sell it and keep the price, or he can keep it and spend on it from his own money. The scholars agreed that if the owner comes before the finder eats it, he has the right to take it.”

The second type: things that could become spoiled, such as watermelons and fruits. The finder in this case should do what is in the owner’s best interests, whether this is eating it and paying for its value, or selling it and keeping its price until the owner comes.
The third type: all other kinds of wealth that are not covered by the first two types, such as money and vessels. All of these must be kept as a trust and announcements should be made in the places where people gather.
It is not permissible for anyone to pick up any kind of lost property unless he can be sure that he will deal with it properly and that he is able to make the necessary announcements, because of the hadith of Zayd ibn Khalid al-Juhani (may Allah be pleased with him), who said: “The Messenger of Allah (peace and blessings of Allah be upon him) was asked about lost gold and silver. He said, ‘Know the details of the purse and the string, then announce it for a year. If no one claims it, then dispose of it, and it is like a trust in your hands. Then if the owner comes along some day, give it to him.” He was asked about the sheep, and he said, “Take it, because either it is for you, or your brother, or the wolf.” He was asked about lost camels, and he said, “What has it got to do with you? It has its water, it can walk to find water and it can eat trees until its owner finds it.” (Agreed upon)
The meaning of the phrase “Know the purse and the string” refers to the kind of purse or wallet that money is kept in and the way it is fastened or tied up.
The meaning of the phrase “then announce it for a year” is that it should be mentioned to people in the places where they gather, such as in market places and by the doors of the mosque etc. “A year” means one full year. In the first week after it is found, it should be announced every day, because it is more likely that the owner will come in that first week. After that it should be announced as often as is customary among the people.

This was the method of announcing lost property in the past. Nowadays people should make lost and found announcements in whatever way is appropriate. What matters is achieving the desired result, so one must do whatever it takes to return property to its rightful owner.

The hadith indicates that it is obligatory to know exactly what the lost property is. The phrase “Know the purse and the strings” indicates that it is obligatory to know what it looks like, so that if the owner comes and describes it properly, it can be given to him, but if his description is at odds with the true description, then it is not permissible to give it to him.
The phrase “If no one claims it, then dispose of it” indicates that the finder takes possession of the property after one year has passed and after announcing it, but he should not dispose of it before he knows exactly what it is, i.e., until he knows “the purse and the string”, and he knows its value, nature and description. If the original owner comes along some time later, and describes it accurately, he should then give it to him, because the Prophet (peace and blessings of Allah be upon him) said: “If someone comes looking for it some day, then give it to him.”

What to do if you find money on the ground
The above discussion makes it clear that there are certain obligations with regard to lost property:

When the property is found, the finder should not take it unless he is certain that he can be trusted to keep it and is able to make the necessary announcements until he finds the owner. Whoever does not feel that he can trust himself to do this is not allowed to pick it up. If he does pick it up, then he is like one who takes something wrongfully, because he took the property of someone else in a manner that is not permissible, and because by taking it he is causing the property of another person to be lost.
Before he takes it, he must be sure of its exact details, by knowing its “purse and string”, and its value, type and appearance. What is meant by its “purse” is knowing the appearance of the container it is in, whether it is a bag or a cloth, and what is meant by its “string” is what it is tied up with, because the Prophet (peace and blessings of Allah be upon him) commanded this, and a command implies that something is obligatory.
It must be announced for a whole year, every day in the first week and then as frequently as is customary. In such announcements one can say for example, “Who has lost something?” and so on. The announcements should be made in places where people gather, such as in marketplaces or at the doors of mosques at prayer time. Announcements should not be made in the mosques themselves, because the mosques are not built for that, and the Prophet (peace and blessings of Allah be upon him) said: “Whoever hears a man making an announcement about lost property in the mosque, let him say, ‘May Allah never return it to you!’”
If someone comes looking for it and describes it properly, it must be given to him without asking him for proof or to swear an oath, because of the command of the Prophet (peace and blessings of Allah be upon him) to that effect, and because his precise description is sufficient in the place of proof or an oath. Indeed, his description may be more clear and more honest than proof or an oath. He should also be given any increase, whether attached or separate. But if he is not able to describe it, then it should not be given to him, because it is a trust in the hands of the finder, and it is not permissible for him to give it to someone who cannot prove that he is the owner.
If the owner does not come forward after it has been announced for an entire year, it becomes the property of the finder, but before he disposes of it he must be sure of its exact description, so that if the original owner comes along some day and describes it, he can give it back to him if it is still there, or he can give him something else if it is no longer there, because his possession of it is limited and expires when the original owner comes along.

It is part of the Islamic teachings on lost property that we should understand how Islam pays attention to the issue of ownership and the sanctity of the Muslim’s property. From all of this we learn that Islam urges us to cooperate in goodness. We ask Allah to help us all to stand firm in Islam and to die as Muslims.
And Allah knows best.