10.15 स्वयम् Thyself, एव only, आत्मना by Thyself, आत्मानम् Thyself, वेत्थ (Thou) knowest, त्वम् Thou, पुरुषोत्तम O Purusha Supreme, भूतभावन O source of beings, भूतेश O Lord of beings, देवदेव O God of,gods, जगत्पते O ruler of the world.Commentary: Purushottama means the best among all Purushas. He assumes the four forms, viz., the source of beings, the Lord of beings, God of gods and ruler of the world. Hence He is called Purushottama.Devadeva is He who is worshipped even by Indra and other gods.Jagatpati The Lord protects the world and guides the people through the instructions given in the Vedas. Hence the name ruler of the world.