Taittirīyopaniṣat 01.11

ā mā yantu brahmacāriṇaḥ svāhā। vi mā yantu brahmacāriṇaḥ svāhā। pra mā yantu brahmacāriṇaḥ svāhā। damā yantu brahmacāriṇaḥ svāhā। śamā yantu brahmacāriṇaḥ svāhā। yaśojanenāni svāhā। śreyān vasyaso'sāni svāhā। taṃ tvā bhaga praviśāni svāhā। sa mā bhaga praviśa svāhā। tasmiṃtsahasraśākhe। ni bhagāhaṃ tvayi mṛje svāhā॥11॥

"Invoking the syllable 'Aa', i.e. auspicious expansion, may the brahmachārins (students) come to me, Offering!
Invoking the syllable 'Vi', i.e. distinguished particularity, may the brahmachārins (students) come to me, Offering!
Invoking the syllable 'Pra', i.e. with directedness and intensity, may the brahmachārins (students) come to me, Offering!
Invoking the syllable 'Da', i.e. self-control, may the brahmachārins (students) come to me, Offering!
Invoking the syllable 'Sha', i.e. tranquillity, may the brahmachārins (students) come to me, Offering!
Glory to all the people, Offering!
Let there be enhanced prosperity, Offering!
O Lord, may I enter you, Offering!
O Lord, may you enter me, Offering!
In that thousand-branched (body); O Lord, I cleanse myself in you, Offering!