«إِلَى أَنْ وَقَفْتُ عَلَى بَابِ دَارٍ وَقُلْتُ عَلَى بِدَارٍ»
Until I stood at a house door and immediately spoke out.
Bāb dār means a house door and ʿalā bidār indicates haste. The close sounds of dār / bidār give the prose a rhythmic finish before verse begins.
Picture the scene: an exhausted traveller, a silent night, a closed doorway, and the possibility that someone inside may listen. The following poem is an urgent request for refuge, not a detached sermon.