[2:262] Those who expend their wealth in the way of God then do not follow up their expenditure with reminder of their generosity and injury, their wage is with their Lord, and no fear shall befall them, neither shall they grieve.
The reminder is witnessing what you did. The injury is pointing out your beneficence to the one who receives it.
It is said they expend what they expend, but they most assuredly do not say anything about their actions or works.
It is said, 'How can you give something and ask for your own right in return for it?'
It is said they do not remind others of what they have done for them, but rather bear witness to the favor of God in granting them success for that.