Here is the Sanskrit anuvad, Hindi anuvad, and English translation of Shraddhatraya-Vibhaga Yoga Chapter 17, Verse 17.24.
Sanskrit
तस्माद ॐ द्दत्युदाहृत्य यज्ञदानतपःक्रियाः । प्रवर्तन्ते विधानोक्ताः सततं ब्रह्मवादिनाम् ॥ १७.२४ ॥
Hindi
इसलिये वेद मन्त्रों का उच्चारण करने वाले श्रेष्ठ पुरुषों की शास्त्र विधि से नियत यज्ञ, दान और तप रूप क्रियाएँ सदा ‘ओउम्’ इस परमात्मा के नाम को उच्चारण करके ही आरम्भ होती हैं|
English
Therefore, dear Arjuna, he who is a devoted follower of the Brahman, begins all acts of spiritual sacrifice, gift-giving, or self-perfection (which is really the achievement of inner-peace with the self), with the word Aum (Aum or the Lord is the very beginning of all things in the universe).