The Messenger of Allah ﷺ said, "When one of you writes a letter, let him sprinkle dust on it, for that is more conducive to the fulfillment of the need."
حدثنا محمود بن غيلان حدثنا شبابة عن حمزة عن أبي الزبير
أن رسول الله ﷺ قال إذا كتب أحدكم كتابا فليتربه فإنه أنجح للحاجة
No references are available.
[Its chain of transmission is extremely daif] * Hamza bin Amr Nasibi is discarded and accused of fabrication. There is another route for it in Ibn Majah, no. 3774, but its chain is also extremely daif.