Allah, the Exalted, says:

"And lower your wings for the believers (be courteous to the fellow-believers).'' (15:88)

"And had you been severe and harsh-hearted, they would have broken away from about you.'' (3:159)

693. `Adi bin Hatim (May Allah be pleased with him) reported: Messenger of Allah (PBUH) said, "Guard yourselves against the Fire (of Hell) even if it be only with half a date-fruit (given in charity); and if you cannot afford even that, you should at least say a good word.''
[Al-Bukhari and Muslim].

Commentary: This Hadith highlights the point that Sadaqah has great benefits and even in its minimum scope and quantity it can ensure our safety against Hell-fire. We are told that if we do not have even a single date or half of it to give to a needy person, we can manage to have the same benefit by talking to him in a compassionate tone, provided we have Faith in our heart.

694. Abu Hurairah (May Allah be pleased with him) reported: The Prophet (PBUH) said, "It is also charity to utter a good word.''
[Al-Bukhari and Muslim].

Commentary:  In Islam, it is not spending money alone that counts as charity; talking to somebody in a decent way also comes in the same context. Now, one can feel the importance Islam gives to moral values and good manners. This saying of Messenger of Allah (PBUH) is part of a long Hadith mentioned earlier. See Hadith No. 122.

695. Abu Dharr (May Allah be pleased with him) reported: Messenger of Allah (PBUH) said, "Do not disdain a good deed, (no matter how small it may seem) even if it is your meeting with your (Muslim) brother with a cheerful face.''
[Muslim].

Commentary:  Every deed approved by the Shari`ah is considered good and rewarding. Howsoever seemingly small people may consider it, it must not be looked at from a highbrow angle. Even to meet people cheerfully is one of the Islamic virtues, though it may appear quite insignificant to some people.