SB 9.13.1

śrī-śuka uvāca
nimir ikṣvāku-tanayo
 vasiṣṭham avṛtartvijam
ārabhya satraṁ so ’py āha
 śakreṇa prāg vṛto ’smi bhoḥ
Word for word: 
śrī-śukaḥ uvāca — Śrī Śukadeva Gosvāmī said; nimiḥ — King Nimi; ikṣvāku-tanayaḥ — the son of Mahārāja Ikṣvāku; vasiṣṭham — the great sage Vasiṣṭha; avṛta — appointed; ṛtvijam — the chief priest of the sacrifice; ārabhya — beginning; satram — the sacrifice; saḥ — he, Vasiṣṭha; api — also; āha — said; śakreṇa — by Lord Indra; prāk — before; vṛtaḥ asmi — I was appointed; bhoḥ — O Mahārāja Nimi.
Translation: 
Śrīla Śukadeva Gosvāmī said: After beginning sacrifices, Mahārāja Nimi, the son of Ikṣvāku, requested the great sage Vasiṣṭha to take the post of chief priest. At that time, Vasiṣṭha replied, “My dear Mahārāja Nimi, I have already accepted the same post in a sacrifice begun by Lord Indra.”