David proposed bringing back the ark, saying Israel had not inquired of it in the days of whom?

Answer: Saul

David told the assembly, "Let us bring back the ark of our God, for we did not inquire of Him in the days of Saul."

“Then let us bring back the ark of our God, for we did not inquire of Him in the days of Saul.””— 1 Chronicles 13:3 (BSB)