CC Antya 4.231

‘ṣaṭ sandarbhe’ kṛṣṇa-prema-tattva prakāśila
cāri-lakṣa grantha teṅho vistāra karila
Word for word: 
ṣaṭ sandarbhe — in the Ṣaṭ-sandarbha; kṛṣṇa-prema-tattva — the truth about transcendental love of Kṛṣṇa; prakāśila — he exhibited; cāri-lakṣa grantha — 400,000 verses; teṅho — he; vistāra karila — expanded.
Translation: 
In the Ṣaṭ-sandarbha Śrīla Jīva Gosvāmī set forth the truths about transcendental love of Kṛṣṇa. In this way he expanded 400,000 verses in all his books.