Albert Barnes Commentary 1 Samuel 9:26

"And they arose early: and it came to pass about the spring of the day, that Samuel called to Saul on the housetop, saying, Up, that I may send thee away. And Saul arose, and they went out both of them, he and Samuel, abroad." — 1 Samuel 9:26 (ASV)

To the top of the house – “On the top.” The bed on which Saul slept was on the top of the house. It is very common in the East to provide extra sleeping accommodations by placing a tent or awning on the housetop.