The people of the fire will call out to the people of Paradise, “Pour on us some water, or some of what Allah has provided you.” -Surah Araaf, verse 50
Charity is not only in “how much you spend” or “how much you donate”. People in the folds of Islam are blessed in every way possible and are rewarded even for saying Salaam.
From removing a stone from the path to smiling at someone, all good deeds are considered charity or Sadaqa.
Offering water to drink is the best form of charity and is a means of forgiveness of sins. Whoever seeks for forgiveness shall give others water to drink.
Ibn-e-Abbas (رضي الله عنه) was asked, “What form of the charity is best?”
He said, ” Giving water to drink.”
Prophet Muhammad (صَلَّى اللّٰهُ عَلَيْهِ وَسَلَّم) said: “Whoever digs a well, no thirsty soul will drink from it whether it be a human, jinn or bird, except that Allah will reward him on the day of Judgement.”
https://www.youtube.com/watch?v=EkHpc_fbP4E&feature=youtu.be