Lord Brahma should not be killed

सतीविवाहशिवलीलावर्णनं नामैकोनविन्शोऽध्यायः

Sati marriage and Shiva activity description Chapter 19

विष्णुरुवाच |

Lord Vishnu said (to Lord Shiva)

सृष्टिस्थित्यन्तकर्माणि करिष्यामः पुनः पुनः |
त्रयो देवा वयं नाथ शिवरूप त्वदाज्ञया || 54 ||

एतस्मिन्निहते शम्भो कस्त्वत्कर्म करिष्यति |
तस्मान्न वध्यो भवता सृष्टिकृल्लयकृद्विभो || 55 ||

Shiva-form, we three Devas will carry out the creation, maintenance and destruction tasks again and again, on your order. Shiva, if you kill him (Lord Brahma), who will do your task? Therefore, creating and destroying God (Shiva), (he – Lord Brahma) should not be killed.