SB 10.39.42-43

tau ratha-sthau katham iha
 sutāv ānakadundubheḥ
tarhi svit syandane na sta
 ity unmajjya vyacaṣṭa saḥ
tatrāpi ca yathā-pūrvam
 āsīnau punar eva saḥ
nyamajjad darśanaṁ yan me
 mṛṣā kiṁ salile tayoḥ
Word for word: 
tau — They; ratha-sthau — present on the chariot; katham — how; iha — here; sutau — the two sons; ānakadundubheḥ — of Vasudeva; tarhi — then; svit — whether; syandane — on the chariot; na staḥ — They are not there; iti — thinking this; unmajjya — rising from the water; vyacaṣṭa — saw; saḥ — he; tatra api — in the same place; ca — and; yathā — as; pūrvam — previously; āsīnau — sitting; punaḥ — again; eva — indeed; saḥ — he; nyamajjat — entered the water; darśanam — the vision; yat — if; me — my; mṛṣā — false; kim — perhaps; salile — in the water; tayoḥ — of Them.
Translation: 
Akrūra thought, “How can the two sons of Ānakadundubhi, who are sitting in the chariot, be standing here in the water? They must have left the chariot.” But when he came out of the river, there They were on the chariot, just as before. Asking himself “Was the vision I had of Them in the water an illusion?” Akrūra reentered the pool.