Don't buy that and do not get back what you gave in charity.
The Book of Gifts - Sahih Muslim 1621 a
This prohibition concerns the one who gives a gift and then seeks to reclaim it, except in the case of a father regarding what he gives to his child. The Prophet (peace be upon him) said: "One who takes back his gift is like a dog which vomits and then returns to its vomit." This illustrates the reprehensible nature of retracting charitable giving, as it nullifies the sincerity and reward of the initial act.
Scholarly Commentary
The prohibition against reclaiming gifts serves to protect the sanctity of charitable acts and maintain social harmony. A gift, once given, becomes the rightful property of the recipient, and seeking its return violates their established rights.
The exception for fathers reflects the unique nature of the parent-child relationship, where gifts often serve as ongoing family support rather than pure charity. However, even in this case, scholars recommend against reclaiming gifts to preserve family bonds.
This teaching emphasizes the importance of sincere intention in giving and warns against treating charity as a temporary loan or conditional transfer of property.