Verse 1.2.86

Sanskrit text, Unicode transliteration, Word-for-word and English translation of verse 1.2.86:

कृष्णाच् छिवस्य भेदेक्षा महा-दोष-करी मता ।
आगो भगवता स्वस्मिन् क्षम्यते न शिवे कृतम् ॥ ८६ ॥

kṛṣṇāc chivasya bhedekṣā mahā-doṣa-karī matā |
āgo bhagavatā svasmin kṣamyate na śive kṛtam || 86 ||

Seeing Śrī Śiva as separate from Bhagavān Śrī Kṛṣṇa is a serious defect. One who commits an offense to Śrī Kṛṣṇa Himself can be tolerated, but it is never possible to tolerate an offender to Śrī Śiva.

Commentary: Dig-darśinī-ṭīkā with Bhāvānuvāda

(By Śrīla Sanātana Gosvāmī himself including a deep purport of that commentary)

In this way, by calling Śrī Śiva the recipient of Śrī Kṛṣṇa’s mercy here, he is prohibiting those who fancy a separatist mentality between Śrī Kṛṣṇa and Śrī Śiva.

In the Nāmāparādhabhañjana-stotra in the Padma Purāṇa (Brahma-khaṇḍa 25.15):

शिवस्य श्री-विष्णोर् य इह गुण-नामादि सकलं
धिया भिन्नं पश्येत् स खलु हरि-नामाहित-करः

śivasya śrī-viṣṇor ya iha guṇa-nāmādi sakalaṃ
dhiyā bhinnaṃ paśyet sa khalu hari-nāmāhita-karaḥ

In this world that person who construes the names, qualities and so on, of Śiva and Viṣṇu with a separatist mood in his heart is certainly an offender towards the holy names of the Lord.

Therefore, Śrī Bhagavān can forgive that person who commits an offense against Him, but He cannot forgive one who commits an offense at the lotus feet of Śrī Śiva. Śrī Śiva is Śrī Kṛṣṇa’s dearmost confidant of bhakti-rasa as well as the topmost of great avatāras.