Srimad-Bhagavatam: Canto 4 - Chapter 1 - Verse 77

Sanskrit:

सर्वतो मन आकृष्य हृदि भूतेन्द्रियाशयम् ।ध्यायन्भगवतो रूपं नाद्राक्षीत्किञ्चनापरम् ॥ ७७ ॥

ITRANS:

sarvato mana ākṛṣyahṛdi bhūtendriyāśayamdhyāyan bhagavato rūpaṁnādrākṣīt kiñcanāparam

Translation:

He completely controlled his senses and their objects, and in this way he fixed his mind, without diversion to anything else, upon the form of the Supreme Personality of Godhead.

Purport:

The yogic principles of meditation are clearly explained here. One has to fix one’s mind upon the form of the Supreme Personality of Godhead without diversion to any other objective. It is not that one can meditate or concentrate on an impersonal objective. To try to do so is simply a waste of time, for it is unnecessarily troublesome, as explained in Bhagavad-gītā.