SB 4.1.39

krator api kriyā bhāryā
 vālakhilyān asūyata
ṛṣīn ṣaṣṭi-sahasrāṇi
 jvalato brahma-tejasā
kratoḥ — of the great sage Kratu; api — also; kriyā — Kriyā; bhāryā — wife; vālakhilyān — just like Vālakhilya; asūyata — begot; ṛṣīn — sages; ṣaṣṭi — sixty; sahasrāṇi — thousand; jvalataḥ — very brilliant; brahma-tejasā — by dint of the Brahman effulgence.
Kratu’s wife, Kriyā, gave birth to sixty thousand great sages, named the Vālakhilyas. All these sages were greatly advanced in spiritual knowledge, and their bodies were illuminated by such knowledge.

Kriyā was the sixth daughter of Kardama Muni, and she produced sixty thousand sages, who were known as the Vālakhilyas because they all retired from family life as vānaprasthas.