gītā mahātmya - Verse śloka 4
śloka 4
gītā sugītā kārtavya kimaṇyaiḥ śāstravistāraiḥ
yā svayaṃ padmanābhāsya mukhapadmadvinihasratā
Translation
The Bhagavad Gita should be studied well. When there is the Bhagavad Gita, which has issued from the lotus mouth of Vishnu, what need is there for so many other scriptures?