Ubayd bin Umayr (may Allah have mercy on him) says that Sayyiduna Umar (may Allah be pleased with him) would say takbir in his tent at Mina; the people in the mosque would hear him and say takbir, the people in the market would hear them and say takbir, until Mina resounded with takbir.
It is reported from Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) that during all those days (of Tashriq) he would say takbir after the prayers, whether he was on his bed, in his tent, sitting or walking.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب صلاة العيدين / 6267