"ओँ तत्सत्" मन्त्र माहात्म्यम्The greatness of the mantra oṁ tat sat
Verse 154
ओँ तत्सदिति मन्त्रेण यो यत् कर्म समाचरेत् । गृहस्थो वाऽप्युदासीनस्तस्याऽभीष्टाय तद् भवेत् ॥ १५४ ॥
ōm̐ tatsaditi mantrēṇa yō yat karma samācarēt | gṛhasthō vā’pyudāsīnastasyā’bhīṣṭāya tad bhavēt || 154 ||
Translation
Whoever does any act with the mantra oṁ tat sat, householder or one who has stood aside, it will be for what he desires.
Word by word
- ōm̐
- oṁ
- tat
- tat
- sad
- (sat) sat
- iti
- thus
- mantrēṇa
- with the mantra
- yō
- (yaḥ) who
- yat
- any
- karma
- act
- samācarēt
- does
- gṛhasthō
- (gṛhasthaḥ) a householder
- vā
- or
- api
- (api) also
- udāsīnas
- (udāsīnaḥ) one who has stood aside
- tasya
- of him
- abhīṣṭāya
- (abhīṣṭāya) for what is desired
- tad
- (tat) that
- bhavēt
- will be
Meaning
The commentary says the greatness of the mantra "oṁ tat sat" begins to be told here, and glosses "samācaret" as "should perform". The Bhagavad Gītā (17.23-27) also teaches that these three words complete an act, and here they become a mantra in their own right.

Commentary
Hariharānanda Bhāratī’s Sanskrit commentary, translated
Now he tells the greatness of the mantra "oṁ tat sat", in the verses beginning "oṁ tat sad iti mantreṇa". Samācaret: should perform (verses 154 to 157).