During the tenth year of the hijrah, as in the preceding one, numerous embassies continued to pour into Medina from all parts of Arabia, to testify to the allegiance of their chiefs and their tribes. Teachers were sent by the Prophet into the different provinces to teach the new converts the principles and precepts of Islam. These teachers were invariably given the following injunctions when they were about to depart on their mission: "Deal gently with the people, and be not harsh; cheer them, and do not look down upon them with contempt. You will meet with many believers in the Holy Scriptures, who will ask you: 'What is the key to heaven?' Answer them that it (the key to heaven) is to bear witness to the divine truth and to do good."
Related Quran Ayaaths of this Hadith.
Surah 3 : Ayah 144 Surah 2 : Ayah 4 Surah 2 : Ayah 23 Surah 2 : Ayah 80 Surah 2 : Ayah 90 Surah 2 : Ayah 93 Surah 2 : Ayah 94 Surah 2 : Ayah 97 Surah 2 : Ayah 105 Surah 2 : Ayah 108 Surah 5 : Ayah 17 Surah 5 : Ayah 48 Surah 5 : Ayah 49 Surah 3 : Ayah 12 Surah 3 : Ayah 20 Surah 3 : Ayah 31 Surah 6 : Ayah 10 Surah 6 : Ayah 11 Surah 4 : Ayah 41"When a person dies, his works end, except for three: ongoing charity, knowledge that is benefited from, and a righteous child who prays for him."
Prophet Mohammed (PBUH)
"The best of what a man leaves behind are three: a righteous child who supplicates for him, ongoing charity the reward of which reaches him, and knowledge that is acted upon after him."
Sunan Ibn Mājah
"Every day two angels come down from Heaven and one of them says, 'O Allah! Compensate every person who spends in Your Cause,' and the other (angel) says, 'O Allah! Destroy every miser.'"
Sahih Bukhari