Looking for resource – textual basis of siddur

My hevruta partner and I are looking for recommendations for a resource to study. We recently did a course with Project Zug called “Unlocking the Prayerbook” where we looked at the textual foundations of prayers in the siddur. Sections from Torah and Talmud were provided in the course readings to provide context and support for the prayer, to help build understanding of why the prayer is worded in the way it is, and provide nuance and layers of meaning to the prayers. It was a great little course, and left us wanting more.

Does anyone have any book (or other resource) recommendations that dive “under the surface” of the siddur? Something that draws direct connections between text from Torah / Talmud and the language of our prayers? We’re looking for something accessible for readers with limited Hebrew. Any ideas appreciated 🙏