Truth is the one undecaying Brahma. Truth is the one undecaying Penance. Truth is the one undecaying Sacrifice. Truth is the one undecaying Veda.
सत्यमेकाक्षरं ब्रह्म सत्यमेकाक्षरं तपः। सत्यमेकाक्षरो यज्ञः सत्यमेकाक्षरं श्रुतम्॥