This verse (chaupai) is from the Balakanda chapter of Shri Ramcharitmanas.

सुमन पाइ मुनि पूजा कीन्ही। पुनि असीस दुहु भाइन्ह दीन्ही॥ सुफल मनोरथ होहुँ तुम्हारे। रामु लखनु सुनि भय सुखारे॥
This verse (chaupai) is Vishwamitra's blessing in Balakanda, given after receiving flowers from Pushpawatika.
Meaning : Receiving the flowers, the sage performed the worship. Then, he blessed both brothers, saying, "May your desires be fulfilled." Hearing this, Ram and Lakshman felt joyful.
Context: where this chaupai appears in Shri Ramcharitmanas
In Balkand, Shri Ram and Lakshman bring flowers from the Pushpavatika for the worship performed by Guru Vishwamitra ji. Receiving the flowers, the sage performed his worship and, pleased, blessed both brothers: may your wishes be fulfilled. Hearing this, Shri Ram and Lakshman were delighted.
Transliteration
Suman Pai Muni Puja Kinhi. Puni Asis Duhu Bhainh Dinhi.. Sufal Manorath Hohun Tumhare. Ramu Lakhanu Suni Bhaye Sukhare..
Word meanings
- Suman = flowers
- Muni = the sage (Guru Vishwamitra)
- Puni = then
- Asis = blessing
- Duhu bhainh = to both brothers
- Sufal manorath = may the wishes be fulfilled
- Sukhare = became happy
As a Shalaka answer
Being a guru's blessing, this is considered a highly auspicious answer. The question is excellent and the wish will be fulfilled; keep your faith, seek the blessings of elders, and begin the work.