Variantly: "What are the testimonies and the statutes, etc.": R. Eliezer says: Whence is it derived that if there were a company of sages or of disciples they must occupy themselves with the halachoth of Pesach until midnight? From "What are the testimonies, etc."
What Are the Testimonies and the Statutes, Etc
Mekhilta Tractate Pischa 18:25