This excerpt is taken from Sheikh Abu Hamza Abdul Khaliq Siddiqi's book Sahih Fazail-e-Amaal.
Sayyiduna Abdullah bin Abbas رضي الله عنهما states that the Messenger of Allah صلی اللہ علیہ وسلم prescribed Sadaqah al-Fitr to purify the fasting person from vain and indecent acts and to provide food for the needy. Therefore, whoever gives it before the Eid prayer, it is accepted as Sadaqah from him, and whoever gives it after the prayer, it is charity but not Sadaqah al-Fitr.
Reference: Sunan Abu Dawood, Book of Zakat, No: 1609. Mustadrak Hakim: 409/1.
Hakim declared it "Sahih" (authentic), and Dhahabi agreed with him.
