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

Expressions researched:
"Lord Brahmā said: My dear Lord Śiva, 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"

Srimad-Bhagavatam

SB Canto 4

Lord Brahmā said: My dear Lord Śiva, 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.

SB 4.6.42, Translation and Purport

Lord Brahmā said: My dear Lord Śiva, 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.

Although Lord Brahmā had received very respectful obeisances from Lord Śiva, he knew that Lord Śiva was in a more exalted position than himself. Lord Śiva's position is described in Brahma-saṁhitā: there is no difference between Lord Viṣṇu and Lord Śiva in their original positions, but still Lord Śiva is different from Lord Viṣṇu. The example is given that the milk in yogurt is not different from the original milk from which it was made.