Rules regarding Debt or Loan

To give loan is among the things which are Mustahab, on which great emphasis has been laid in the Holy Qur'an and in the Traditions (Ahadith). The Holy Prophet has been reported to have said that whoever gives loan to his Muslim brother, his wealth flourishes, and the angels invoke Divine mercy for him, and if he is lenient with his debtor, he will pass over the Bridge (Sirat) swiftly. And if a Muslim denies his brethren-in-faith a loan, Paradise becomes forbidden (Haraam) for him.