Skandapurana 6.3.231.30

6.3.231.30

tathaiva brahmaṇā siddhyai saptatīrthānyavīvadat .
triṣu ca brahmaṇaḥ pūjā brahmeśāścaturo'pare .
aṣṭāviṃśanmayā khyātā yathāsaṅkhyaṃ yathākramam .. 231.30 ..

Likewise, he spoke of seven sacred fords for Brahmā, for the attainment of perfection;
in three of them, Brahmā is worshipped, and the other four are Brahmeśas.
Twenty-eight have been declared by me according to number and order. // 231.30