Sadaqah

The Prophet, peace and blessings be upon him, said, “The shade of the believer on the Day of Resurrection is his charity.”

Source: Musnad Aḥmad 23490

Sadaqah comes from the root word sidq which means sincerity.

it is an indication of sincerity of imaan (faith) and confirms ones sincere devotion to Allah alone.

Those who spend their wealth in the cause of Allah and do not follow their charity with reminders of their generosity or hurtful words - they will get their reward from their Lord, and there will be no fear for them, nor will they grieve.

Holy Qur’an, al-Baqarah 262

The word sadaqah can be applied to all kinds of good deeds.

the Prophet (peace and blessings of Allaah be upon him) said: “Every good deed is a charity.”

Those who (in charity) spend of their goods by night and by day, in secret and in public have their reward with their Lord. On them shall be no fear nor shall they grieve. (2:274)

لَن تَنَالُوا۟ ٱلْبِرَّ حَتَّىٰ تُنفِقُوا۟ مِمَّا تُحِبُّونَ

"By no means shall you attain Al-Birr (piety, righteousness, etc., it means here Allah's Reward, i.e. Paradise), unless you spend (in Allah's Cause) of that which you love."
[Sūrah Āli 'Imrān 3:92]

Which brings us to the understanding that when giving out sadaqah, it is necessary to give out of what we love and not merely giving out things only to get rid of them.

This can be also be understood through the prophet’s صلى الله عليه وسلم statement “None of you are true believers until you love for your brother what you love for yourself.”