Sayyiduna Abu al-Darda' (may Allah be pleased with him) relates this as a "marfu'" hadith: The Prophet (peace and blessings be upon him) said: "Three things are among the character traits of prophethood: hastening the breaking of the fast, delaying the pre-dawn meal (suhur), and placing the right hand over the left during prayer."
Al-Tabarani recorded it in al-Mu'jam al-Kabir both as a "marfu'" hadith and as a "mawquf" report from Sayyiduna Abu al-Darda' (may Allah be pleased with him). The "mawquf" version is authentic; among the narrators of the "marfu'" version is someone whose biography I have not found anyone giving. (Allamah al-Haythami says:) I say: Other hadiths of this kind will come later in the chapter on fasting, if Allah wills.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الصلاة / 2611
Hadith Gradingمحدثین:موقوف صحيح
Hadith Takhrij«أخرجه الأوسط في السنن والإجماع والاختلاف برقم: 1283»