It is narrated from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) that on the day of departure from Mina (Yawm al-Nafr) he would say the takbir aloud and would order all the people around him to "say the takbir (proclaim the greatness of Allah)"; he did all this in obedience to this exalted saying of Allah Almighty: "Then when you have completed your rites (of Hajj), remember Allah" [Surah al-Baqarah: 200].
Imam Musaddad (may Allah have mercy on him) narrated this report in his Musnad.
Hadith Referenceالمطالب العالية بزوائد المسانيد الثمانية / أبواب الجمعة / 754
Hadith Gradingمحدثین:إسناده حسن
Hadith Takhrij«حکم الحدیث المطالب العالیہ محققاً تنسیق د. سعد بن ناصر بن عبد العزيز الشَّثري- مکتبہ شاملہ :حسن لغيره. » «أخرجه البيهقي فى«سننه الكبير» برقم: 6357، 10259، وأورده ابن حجر فى "المطالب العالية"، 754»