Valmiki Ramayana Sundara Kanda Sarga 59 Shloka 19
Original Shlokaअश्विनोर्माननार्थं हि सर्वलोकपितामहः। सर्वावध्यत्वमतुलमनयोर्दत्तवान्पुरा।।5.59.19।।
1 source checked for this shloka
पुरा earlier, सर्वलोकपितामहः Brahma the grandfather of all worlds, अश्विनोः for Aswini sons, माननार्थम् to honour, अनयोः given, अतुलम् immeasureable, सर्वावध्यत्वम् invulnerability, दत्तवान् given.
"Earlier Brahma, the grandsire of all worlds has given the Aswini sons immeasurable invulnerability to honour them.