31. “Towns which We had blessed”: The lands of Syria and Palestine, which have been generally mentioned in the Quran by this title. For instance, in (Surah Al-Aaraf, Atyat 137), (Surah Bani-Israil, Ayat 1), (Surah Al-Anbiya, Ayats 71, 81).
“Visible towns”: Habitations situated on the highway and not inside the country. It may also mean that the habitations were not very far apart but contiguous so that as the outlying areas of one habitation came to an end those of the other started coming into view.
“And We made the stages (of journey) between them easy” implies that from the Yaman to the borders of Syria the whole journey passed through inhabited lands, and the distances between one station and another were known and determined. That makes the distinction between the journey through inhabited land and the journey through uninhabited desert area. In the desert the traveler continues to travel as long as he wills and halts when tired. Contrary to this, in settled areas as the distance between one habitation and the other is well known, the traveler can plan beforehand when he would break his journey, where he would have his midday rest and when he would stay for the night.