First of all, it should be noted that giving in charity is a highly rewarded act, having that it is given with an intention purely for Allah alone.

It was narrated that Abu Hurayrah (may Allah be pleased with him) said: The Messenger of Allah (peace and blessings be upon him) said: “Whoever gives charity equal to a date from good (halal) earnings – for Allah does not accept anything but that which is good – Allah will take it in His right hand and tend it for the one who gave it as any one of you tends his foal, until it becomes like a mountain.” (Al-Bukhari and Muslim)

Also, it was narrated from Abu Hurayrah (may Allah be pleased with him) that the Prophet (peace and blessings of Allah be upon him) said: “There is no day on which the people get up but two angels come down and one of them says, ‘O Allah, give in compensation to the one who spends (in charity),’ and the other says, ‘O Allah, destroy the one who withholds.’”  (Al-Bukhari and Muslim)

As regards the increase of money when giving from it in charity, fairly this is an absolute fact. The Prophet (peace be upon him) attested to that and said: “Three things I swear about them and narrate to you, so learn them: no person’s wealth decreases because of charity, no person is wronged and bears it with patience but Allah will increase him in honour, and no person opens the door of begging but Allah will open the door of poverty to him.” (Al-Tirmidhi)

The Hadith indicates that one’s money does not decrease by giving in charity, because Allah blesses the remaining money and increases it, so that a Muslim merchant who gives in charity Allah helps him and facilitates for him the causes of plentiful gaining, so he may gets great profit from every deal he does and from every bargain he engages in. Also, a Muslim employee who gives Sadaqah, Allah rewards him by protecting him from various diseases that can take out a lot of money, and makes him successful in his work so that he gains more bonuses and raises.

The increase in money must not be tangible, but it is rightfully noticeable, through invaluable donations and favors which Allah grants a Muslim donor, including good health and peace of mind, protection against diseases, cure of illnesses, great reward in the hereafter and many other good things.

In fact, a person who has been protected from an illness that would have cost him a lot of money, or protected from loss in his trade and failure of his projects, has gained more money and his money has increased.