In the Upanishad , Lord Shiva adapted Sri Rudram mantras.

mā nas toke tanaye mā na āyuṣi
mā no goṣu mā na aśveṣu rīriṣaḥ
vīrān mā no rudra bhāmito
vadhīr haviṣmantaḥ sadāmit tvā havāmahe ( SV Up IV-22)


O Rudra, do not, in Thy wrath, destroy our children and grand—children. Do not destroy our lives; do not destroy our cows or horses; do not destroy our strong servants. For we invoke Thee always, with oblations, for our protection.


The above verse is also taken 'AS IT IS' from Sri Rudram portion of Yajurveda. Here Rudra is asked to show mercy upon the progency. It is typical to Rudra in vedas.
Adapted from:

Manastoke tanaye ma na ayushhi ma no goshhu ma no ashveshhu ririshhah
Viranma no rudra bhamitoavadhi rhavishhmanto namasa vidhema te ( Yajur veda TS IV-5-10-f)

Lord Rudra! Getting angry at our transgressions hurts not only our children, our sons in particular, but also our cattle and horses, and our warriors. Making offerings into the sacred fire, we shall serve and calm you by our Namaskars (salutations).

Prakriti is perishable but Hara is imperishable.

By knowing the deity all pashas ie., Bondages will be gone.

Rishi Svetasvatara devoted himself heart and soul to Lord Rudra. He was a devotee of Lord Shiva. He worshiped 'Hara'. He surrendered to 'Maheswara'. He took refuge of Ishana alone. By surrendering to Pashupati he broke all Paashaas(Bondage) and finally attained salvation by the grace of Lord Rudra.

Svetasvatara worshiped Lord Shiva who is beyond form and name. He did Rudropasana. He meditated on the benign aspect of Lord Rudra. He realised that all gods including Vishnu were created by Lord Rudra alone. Rudra alone bestowed powers upon the gods. He called Rudra with various names like Shiva, Maheswara, Hara, ishana, pashupati, Parameswara..etc. In the Upanishad , he adapted Sri Rudram mantras.

Om Namah Shivay.