The Spandapradipika is a commentary on the Spanda Karika, an early, seminal Kashmiri Saiva text. This commentary is by Bhagavadutpala, also known as Utpala Vaisnava, who lived in 10th century Kashmir. It is important both because it is early and especially because it contains copious references to Pancaratra sources--the earliest dateable ones so far recovered. Mark Dyczkowski has translated this text in his book Stanzas on Vibration. The Spandakarika with Four Commentaries.
Spandapradipika A Commentary on the Spandakarika by Bhagavadutpalacarya