Quran

Allah will come to the aid of a generous man whenever he stumbles, while the wrongdoer who transgressed rather than doing good will have no help from Allah. Al-Biqai: 1/525.
Question: After urging the believers to give to charity, the verse concludes with: (But the wrongdoers have no helpers). Why?

This indicates that charity given secretly to the poor is better than charity given openly, but if charity is not being given to the poor, then the verse implies that giving secretly is not better than that which is given openly. It depends on what serves a greater purpose. If giving charity openly makes acts of worship visible, and encourages others to follow, then it is better than doing it in private. Al-Saadi: 116.
Question: When giving charity, which is better: doing it publicly or privately?

This indicates that concealing charity is better than disclosing it because it is further from showing off. Ibn Kathir: 1/305.
Question: Why is concealing charity is better than disclosing it?

Spend only for the sake of Allah without causing hurt, reminding others of it, showing off nor spending out of inferior things. Al-Alusi: 3/46.
Question: List some of the pitfalls that nullify the charities or reduce their reward?

An ignorant person would think they were self-sufficient because they were not asking others. (Restraint) is refrainment from requesting. (You will know them by their sign): Their faces show tiredness, destitution and lack of blessings. It was also said: Humbleness or prostration marks. (They do not ask people persistently): They ask people graciously or they never ask at all. Ibn Juzay: 1/127.
Question: What are the qualities for which Allah praised the poor believers in this verse?

The poor immigrants (Muhajireen) are singled out because they were the only poor people at that time. They were the people of the Suffah (verandah), and they about four hundred men. That was because the poor used to come to the Messenger of Allah (r), and they had neither family nor property and so a verandah (Suffah) was built for them in the mosque of the Messenger of Allah (r), which is why they were called the People of the Suffah. Al-Qurtubi: 4/371.
Question: Why were the people of "Suffah" poor?

The (night) is mentioned before (day) and (secret) is before (public), to indicate the advantage of concealment over disclosure. Al-Alusi: 3/47.
Question: Why is (night) mentioned before (day), and (secret) before (public)?