Bhagavad Gita 14.18 Chapter 14, Verse 18

ऊर्ध्वं गच्छन्ति सत्त्वस्था मध्ये तिष्ठन्ति राजसाः ।
जघन्यगुणवृत्तिस्था अधो गच्छन्ति तामसाः ॥१४.१८॥

ūrdhvaṃ gacchanti sattvasthā madhye tiṣṭhanti rājasāḥ
jaghanyaguṇavṛttisthā adho gacchanti tāmasāḥ

Meaning

Those established in sattva rise upward, the rajasic stay in the middle, and the tamasic, abiding in the lowest quality, go downward.

Newly written by Bhajan Dhun — scholarly review in progress.

Reference: Bhagavad Gita 14.18 (Chapter 14, The Three Qualities of Nature (Gunatraya Vibhaga Yoga), Verse 18)