Rig Veda 1.1.9

The mantra in english 

sa nah piteva sunave agne supayano bhava
sacasva nah svastaye

The meaning of Rigveda 1.1.9

As a father is ever one with his child in love, so may Agni, lord of life and light and father guardian of His creation, be ever close to us in love and benediction. Father of us all, give us the grace of life divine.

Mantra in sanskrit

स नः पितेव सूनवेऽग्ने सूपायनो भव । सचस्वा नः स्वस्तये ॥