Fath al-Rabbani

It is narrated from Sayyidah ‘Adi bin ‘Amirah (may Allah be pleased with him) that when the Noble Prophet (peace and blessings be upon him) performed prostration, the whiteness of his armpits would become visible. Similarly, when he turned to the right to say salam, he would turn his face so much that the whiteness of his cheek would become visible, and when he turned to the left to say salam, he would turn his face so much that the whiteness of his cheek would become visible from the left side.