Srimad Bhagavatam Canto 08, Chapter 07, Text 25

SB 8.7.25

tvam sabda-yonir jagad-adir atma
 pranendriya-dravya-gunah svabhavah
kalah kratuh satyam rtam ca dharmas
 tvayy aksaram yat tri-vrd-amananti
 
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
O lord, you are the original source of Vedic literature. You are the original cause of material creation, the life force, the senses, the five elements, the three modes and the mahat-tattva. You are eternal time, determination and the two religious systems called truth [satya] and truthfulness [rta]. You are the shelter of the syllable om, which consists of three letters a-u-m.
Srimad Bhagavatam Canto 08, Chapter 07, Text 24
Srimad Bhagavatam Canto 08, Chapter 07, Text 26