SB 4.16.24

eṣo ’śvamedhāñ śatam ājahāra
 sarasvatī prādurabhāvi yatra
ahārṣīd yasya hayaṁ purandaraḥ
 śata-kratuś carame vartamāne
Word for word: 
eṣaḥ — this King; aśvamedhān — sacrifices known as aśvamedha; śatam — one hundred; ājahāra — will perform; sarasvatī — the river of the name Sarasvatī; prādurabhāvi — became manifest; yatra — where; ahārṣīt — will steal; yasya — whose; hayam — horse; purandaraḥ — the Lord Indra; śata-kratuḥ — who performed one hundred sacrifices; carame — while the last sacrifice; vartamāne — is occurring.
Translation: 
At the source of the river Sarasvatī, this King will perform one hundred sacrifices known as aśvamedha. In the course of the last sacrifice, the heavenly King Indra will steal the sacrificial horse.