Matsya Purana 273.43

273.43

tayormadhye tu nakṣatraṃ dṛśyate yatsamaṃ divi.
tena saptarṣayo jñeyā yuktā vyomni śataṃ samāḥ .. 273.42

The two front stars of the Great Bear, which are seen when risen at night, the lunar constellation which is seen situated equally between them in the sky, the Great Bear is to be known as conjoined with that constellation 100 years in the sky —42 43 (Pargiter)