It is narrated from Sayyidah Aisha (may Allah be pleased with her) that the Messenger of Allah (peace and blessings of Allah be upon him) used to pray on a small mat. And he (peace be upon him) said: "O Aisha, take this mat away from us, for I feared that it might put people into trial (fitnah)."
Hadith Referenceصحيح ابن خزيمه / جماع أبواب الصلاة على البسط / 1011