Katha Upanishad Verse 1.3.13

Yama provides a systematic method for meditation: control the outgoing senses (speech) by the mind, bring the mind under the intellect, merge the intellect into the Higher Self (Mahat), and finally settle into the Peaceful Atman or Supreme Intelligence.

Sanskrit Verse

यच्छेद्वाङ्मनसी प्राज्ञस्तद्यच्छेज्ज्ञान आत्मनि ।
ज्ञानमात्मनि महति नियच्छेत्तद्यच्छेच्छान्त आत्मनि ॥ १३ ॥

Transliteration

yacchedvāṅmanasī prājñastadyacchejjñāna ātmani |
jñānamātmani mahati niyacchettadyacchecchānta ātmani || 13 ||

Translation

Let the intelligent man sink speech into mind, sink that into intelligence and intelligence into the great atman and sink that into the peaceful atman.