Is it considered a sin or does it nullify the reward if a wife retracts from giving her husband the full amount he requested to present as charity to a friend, after she had initially agreed to give him the full amount, and then later agreed to give him only half the amount?

The prevailing view among the majority of scholars is that a sadaqah (definition) (charitable donation) is not complete and does not leave the possession of its owner until it is seized by the poor person or their representative. As long as it remains in the owner's hand, they have the right to retract it, though it is preferable for them to proceed with it. Thus, sadaqah is not considered to have occurred until it reaches the poor person. Therefore, there is no sin upon the questioner for giving her husband half the amount to donate as sadaqah, and she will be rewarded for it. It is better for her to complete the full amount, unless doing so would be detrimental to her essential needs.