CC Madhya 21.30

apāra aiśvarya kṛṣṇera — nāhika gaṇana
śākhā-candra-nyāye kari dig-daraśana
apāra — unlimited; aiśvarya — opulence; kṛṣṇera — of Lord Kṛṣṇa; nāhika gaṇana — there is no estimation; śākhā-candra-nyāye — according to the logic of seeing the moon through the branches of a tree; kari — I make; dik-daraśana — an indication only.
“No one can estimate the opulence of Kṛṣṇa. That is unlimited. However, just as one sees the moon through the branches of a tree, I wish to give a little indication.”

First a child is shown the branches of a tree, and then he is shown the moon through the branches. This is called śākhā-candra-nyāya. The idea is that first one must be given a simpler example. Then the more difficult background is explained.