It is narrated from Hazrat Aisha that the Prophet (peace be upon him) used to perform two short rak'ahs after the mu'adhdhin gave the adhan, then he would lie down on his right side until the mu'adhdhin would come and inform the Prophet (peace be upon him) about the prayer.
Hadith Referenceمسند احمد / مسند النساء / 24550
Hadith Gradingحکم دارالسلام:حديث صحيح، وهو مكرر: 24537