Shiva Purana
अनागताश्च सप्तैते कल्पेऽस्मिन्मनवस्स्मृताः ॥ अनागताश्च सप्तैव स्मृता दिवि महर्षयः ॥ ३३ ॥
The future Manus in this Kalpa will be seven. The future great sages will also be seven in each Manvantara in the heaven.
english translation
anAgatAzca saptaite kalpe'sminmanavassmRtAH ॥ anAgatAzca saptaiva smRtA divi maharSayaH ॥ 33 ॥
hk transliteration by Sanscript