Closing attribution 23
इति श्रीमन्महामाहेश्वराचार्याभिनवगुप्तपादपद्मोपजीवि-श्रीक्षेमराजविरचितायां शिवसूत्रविमर्शिन्यां शाम्भवोपायप्रकाशनं नाम प्रथम उन्मेषः ॥ १ ॥
In plain words
Thus ends the first unmeṣa, called the Revealing of the Śāmbhava Upāya, in the Śivasūtravimarśinī composed by the glorious Kṣemarāja, who lives at the lotus feet of the glorious Abhinavagupta, great devotee of the Great Lord and teacher.