Kauṣītaki Upaniṣad 1.1.1

1.1.1

citro ha vai gārgyāyaṇir yakṣyamāṇa āruṇiṃ vavre /

1. Citra Gāṅgyāyani, verily, being about to sacrifice, chose Āruṇi. He then dispatched his son Śvetaketu, saying: 'You perform the sacrifice.' When he had arrived, he asked of him: 'Son of Gautama, is there a conclusion [of transmigration] in the world in which you will put me? Or is there any road? Will you put me in its world?'