'Allah will show compassion to those who show kindness while buying and selling, and recovering debts.'

HADITH OF AL-BUKHARI
On the Authority of Jabir

'One who denies an heir his legacy will be denied the legacy of Paradise by the Almighty.'

HADITH OF IBN MAJAH
On the Authority of Anas ibn Malik

'One who makes sacrifices for the sake of God will have all his sins pardoned, except for his debts.'

HADITH OF MUSLIM
On the Authority of 'Abdullah ibn 'Umar

'Pay the labourer his wages even before his sweat dries up.'

HADITH OF IBN MAJAH
On the Authority of 'Abdulla ibn 'Umar

"The observance of three days' fast every month and that of Ramadan every year is a perpetual fasting. I seek from Allah that fasting on the day of Arafah may atone for the sins of the preceding and the coming years, and I seek from Allah that fasting on the day of Ashura may atone for the sins of the preceding year."

- Sahih Muslim

'There was a man who used to give loans to poor people. When his assistant had to go to them to recover the loans, he would urge him to be forgiving to those who were not able to pay back his loans with ease, believing that, in that way, perhaps God would show him forgiveness. When that man came face to face with the Almighty, He forgave him.'

HADITH OF AL-BUKHARI AND MUSLIM
On the Authority of Abu Hurayrah

"If a man commits something to your care, be sure to return it to him. Never betray anyone's trust, not even if the person concerned has failed to stand by his commitments to you."

HADITH OF AT-TIRMIDHI
On the Authority of Abu Hurayrah

When Allah's Messenger (sallallaahu 'alaihi wasallam) came to Medina, he found the jews fasting on the day of 'Ashura' (i.e. 10th of Muharram). They used to say: "This is a great day on which Allah saved Moses and drowned the folk of Pharaoh. Moses observed the fast on this day, as a sign of gratitude to Allah."
The Prophet said, "I am closer to Moses than they." So, he observed the fast (on that day) and ordered the Muslims to fast on it.

- Sahih Bukhari

"Save youself from the curse of an oppressed person, who seeks his rights from God, for God never denies the righteous their rights."

HADITH OF AL-BAYHAQI
On the Authority of 'Ali ibn Abi Talib

'Beware of suspicion (about others) as suspicion is the falsest talk,
and do not spy upon each other,
and do not listen to the evil talk of the people about others' affairs,
and do not have enmity with one another, but be brothers.
And none should ask for the hand of a girl who is already engaged to his (Muslim) brother, but one should wait till the first suitor marries her or leaves her.'

- Sahih Bukhari