Bs 5.45

kṣīraṁ yathā dadhi vikāra-viśeṣa-yogāt
sañjāyate na hi tataḥ pṛthag asti hetoḥ
yaḥ śambhutām api tathā samupaiti kāryād
govindam ādi-puruṣaṁ tam ahaṁ bhajāmi
Word for word: 
kṣīram — milk; yathā — as; dadhi — yogurt; vikāra-viśeṣa — of a special transformation; yogāt — by the application; sañjāyate — is transformed into; na — not; hi — indeed; tataḥ — from the milk; pṛthak — separated; asti — is; hetoḥ — which is the cause; yaḥ — who; śambhutām — the nature of Lord Śiva; api — also; tathā — thus; samupaiti — accepts; kāryāt — for the matter of some particular business; govindam — Govinda; ādi-puruṣam — the original person; tam — Him; aham — I; bhajāmi — worship.
Translation: 
Just as milk is transformed into curd by the action of acids, but yet the effect curd is neither same as, nor different from, its cause, viz., milk, so I adore the primeval Lord Govinda of whom the state of Śambhu is a transformation for the performance of the work of destruction.
Purport: 

(The real nature of Śambhu, the presiding deity of Maheśa-dhāma, is described.) Śambhu is not a second Godhead other than Kṛṣṇa. Those, who entertain such discriminating sentiment, commit a great offense against the Supreme Lord. The supremacy of Śambhu is subservient to that of Govinda; hence they are not really different from each other. The nondistinction is established by the fact that just as milk treated with acid turns into curd so Godhead becomes a subservient when He Himself attains a distinct personality by the addition of a particular element of adulteration. This personality has no independent initiative. The said adulterating principle is constituted of a combination of the stupefying quality of the deluding energy, the quality of nonplenitude of the marginal potency and a slight degree of the ecstatic-cum-cognitive principle of the plenary spiritual potency. This specifically adulterated reflection of the principle of the subjective portion of the Divinity is Sadāśiva, in the form of the effulgent masculine-symbol-god Śambhu from whom Rudradeva is manifested. In the work of mundane creation as the material cause, in the work of preservation by the destruction of sundry asuras and in the work of destruction to conduct the whole operation, Govinda manifests Himself as guṇa-avatāra in the form of Śambhu who is the separated portion of Govinda imbued with the principle of His subjective plenary portion. The personality of the destructive principle in the form of time has been identified with that of Śambhu by scriptural evidences that have been adduced in the commentary. The purport of the Bhāgavata ślokas, viz., vaiṣṇavānāṁ yathā śambhuḥ, etc., is that Śambhu, in pursuance of the will of Govinda, works in union with his consort Durgādevī by his own time energy. He teaches pious duties (dharma) as stepping-stones to the attainment of spiritual service in the various tantra-śāstras, etc., suitable for jīvas in different grades of the conditional existence. In obedience to the will of Govinda, Śambhu maintains and fosters the religion of pure devotion by preaching the cult of illusionism (Māyāvāda) and the speculative āgama-śāstras. The fifty attributes of individual souls are manifest in a far vaster measure in Śambhu and five additional attributes not attainable by jīvas are also partly found in him. So Śambhu cannot be called a jīva. He is the lord of jīva but yet partakes of the nature of a separated portion of Govinda.