Srimad-Bhagavatam: Canto 2 - Chapter 1 - Verse 41

Sanskrit:

नान्तं विदाम्यहममी मुनयोऽग्रजास्तेमायाबलस्य पुरुषस्य कुतोऽवरा ये ।गायन् गुणान् दशशतानन आदिदेव:शेषोऽधुनापि समवस्यति नास्य पारम् ॥ ४१ ॥

ITRANS:

nāntaṁ vidāmy aham amī munayo ’gra-jās temāyā-balasya puruṣasya kuto ’varā yegāyan guṇān daśa-śatānana ādi-devaḥśeṣo ’dhunāpi samavasyati nāsya pāram

Translation:

Neither I nor all the sages born before you know fully the omnipotent Personality of Godhead. So what can others, who are born after us, know about Him? Even the first incarnation of the Lord, namely Śeṣa, has not been able to reach the limit of such knowledge, although He is describing the qualities of the Lord with ten hundred faces.

Purport:

The omnipotent Personality of Godhead has three primary potencies, namely the internal, external and marginal potencies, with unlimited expansions of these three energies. As such, the expansions of His potentcies can never be calculated by anyone because even the Personality of God Himself, as the incarnation of Śeṣa, cannot estimate the potencies, although He has been describing them continuously with His one thousand faces.