Bala Kand Verse 182
देत चापु आपुहिं चलि गयऊ। परसुराम मन बिसमय भयऊ ॥
deta cāpu āpuhiṃ cali gayaū| parasurāma mana bisamaya bhayaū ||
deta capu apuhim cali gayau parasurama mana bisamaya bhayau
As he handed over the bow, it flew of its own accord into Shree Rama's hands. Parashuram's heart was filled with wonder — he now knew he stood before Lord Vishnu himself.
(श्रीराम के हाथ में) धनुष देते ही (परशुराम के हाथ से) वह स्वयं चला गया। परशुराम के मन में अत्यंत विस्मय हुआ — वे समझ गए कि यह साक्षात् भगवान् विष्णु हैं।
This is verse 182 of 211 in Bala Kand (बालकाण्ड), from the section “Parashuram Samvad” of Goswami Tulsidas’ Ramcharitmanas.