Gita Mahatmya
Mahābhārata, Bhīṣma-parva 43.3
These verses glorify the Bhagavad-gītā. They come from other scriptures and are not verses of the Bhagavad-gītā itself. Each one carries its own source.
-
Gītā-māhātmya
गीता गङ्गा च गायत्री गोविन्देति हृदि स्थिते ।
चतुर्गकारसंयुक्ते पुनर्जन्म न विद्यते ॥gītā gaṅgā ca gāyatrī govindeti hṛdi sthite
caturgakārasaṁyukte punarjanma na vidyateGītā, Gaṅgā, Gāyatrī and Govinda: these four names begin with “ga”. One who keeps them in his heart is not born again.
Source: Mahābhārata, Bhīṣma-parva 43.3