Canto 1 - Boyhood
Bāla-kāṇḍa
Chapter 8: Daśaratha Decides to Perform the Aśvamedha Sacrifice
Text 1.8.8

मम लालप्यमानस्य पुत्रार्थं नास्ति वै सुखम्।
तदर्थं हयमेधेन यक्ष्यामीति मतिर्मम॥

mama lālapyamānasya putrārthaṁ nāsti vai sukham
tad-arthaṁ haya-medhena yakṣyāmīti matir mama

mama lālapyamānasya = I have been lamenting; putra-artham = for want of a son; na asti = without; vai = any; sukham = happiness; tat-artham = to get a son; haya-medhena = in an Aśvamedha sacrifice; yakṣyāmi = I should engage; iti = that; matiḥ mama = therefore, I have concluded.

I have been lamenting without any happiness, for want of a son. Therefore, I have concluded that I should engage in an Aśvamedha sacrifice to get a son.