to stay (at); to stop (at)
「宿す」 has another reading with different meanings.
旅の途中、寺に宿した。
On the way, I stayed at a temple.
峠を越えたら麓の村に宿す予定だ。
After crossing the pass, I plan to stay in the village at the foot of the mountain.
旅籠に宿している旅人の声が廊下まで聞こえた。
The voices of travelers staying at the inn could be heard in the hallway.