It is narrated from Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) that when the Prophet (peace and blessings be upon him) was in the tashahhud of the two rak'ahs, it was as though he were sitting on heated stones. The narrator Sa'd bin Ibrahim said: I would ask Abu Ubaydah: Did this state last until he stood up? And he would say: Yes, until he stood up.
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 10247