Agnipurana 21.9

21.9

śivapūjātha sāmānyā pūrvaṃ nandinamarcayet /
mahākālaṃ yajedgaṅgāṃ(3) yamunāñca gaṇādikam //

Now the general worship of Śiva: first one should revere Nandin; / one should worship Mahākāla, Gaṅgā, Yamunā, the Gaṇas, and the rest;