SB 4.6.42
brahmovaca
jane tvam isam visvasya
jagato yoni-bijayoh
sakteh sivasya ca param
yat tad brahma nirantaram
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Lord Brahma said: My dear Lord Siva, I know that you are the controller of the entire material manifestation, the combination father and mother of the cosmic manifestation, and the Supreme Brahman beyond the cosmic manifestation as well. I know you in that way.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Although Lord Brahma had received very respectful obeisances from Lord Siva, he knew that Lord Siva was in a more exalted position than himself. Lord Siva’s position is described in Brahma-samhita: there is no difference between Lord Visnu and Lord Siva in their original positions, but still Lord Siva is different from Lord Visnu. The example is given that the milk in yogurt is not different from the original milk from which it was made.