The Rāmāyaṇa of Vālmīki 2.37.2

2.37.2

yāvad rājā priyaṃ putraṃ paśyaty atyantadhārmikam
tāvad vyavardhatevāsya dharaṇyāṃ putradarśane

While yet the dust was seen afar
That marked the course of Ráma's car,
The glory of Ikshváku's race
Turned not away his eager face.
While yet his duteous son he saw
He could not once his gaze withdraw,
But rooted to the spot remained
With eyes that after Ráma strained.
But when that dust no more he viewed,
Fainting he fell by grief subdued.