CC Madhya 20.362

ei saba kārya — tāṅra taṭastha-lakṣaṇa
anya avatāra aiche jāne muni-gaṇa
Word for word: 
ei saba kārya — all these activities; tāṅra — His; taṭastha-lakṣaṇa — marginal characteristics; anya avatāra — another incarnation; aiche — in that same way; jāne — know; muni-gaṇa — the great saintly persons like Vyāsadeva.
Translation: 
“All these activities are His marginal characteristics. Great saintly persons understand the incarnations of the Supreme Personality of Godhead by the indications of the two characteristics known as svarūpa and taṭastha. All the incarnations of Kṛṣṇa should be understood in this way.