Caitanya-caritāmṛta 9.211-212
sītayārādhito vahniś chāyā-sītām ajījanat tāṁ jahāra daśa-grīvaḥ sītā vahni-puraṁ gatāparīkṣā-samaye vahniṁ chāyā-sītā viveśa sā vahniḥ sītāṁ samānīya tat-purastād anīnayat
[seetayaaraadhito vahnish chaayaa-seetaam ajeejanat taam jahaara dasha-greevah seetaa vahni-puram gataapareekshaa-samaye vahnim chaayaa-seetaa vivesha saa vahnih seetaam samaaneeya tat-purastaad aneenayat]
Blended reading (Sanskrit + English inline)
sītayārādhito vahniś chāyā-sītām ajījanat tāṁ jahāra daśa-grīvaḥ sītā vahni-puraṁ gatāparīkṣā-samaye vahniṁ chāyā-sītā viveśa sā vahniḥ sītāṁ samānīya tat-purastād anīnayat
“When he was petitioned by mother Sītā, the fire-god, Agni, brought forth an illusory form of Sītā, and Rāvaṇa, who had ten heads, kidnapped the false Sītā. The original Sītā then went to the abode of the fire-god. When Lord Rāmacandra tested the body of Sītā, it was the false, illusory Sītā that entered the fire. At that time the fire-god brought the original Sītā from his abode and delivered her to Lord Rāmacandra.”
Purport
These two verses are taken from the Kūrma Purāṇa.
— A.C. Bhaktivedanta Swami Prabhupāda
My note
Source: vedabase.io