"And indeed, you"—O company of polytheists—"pass by them"—upon their dwellings—"in the morning," meaning: in the daytime. He means: during the day while traveling to Greater Syria, and during your return with trade, and you see what was done to them.
﴿وانكم﴾ [يَا معشر الْمُشْركين] ﴿لَتَمُرُّونَ عَلَيْهِمْ﴾ [على مَنَازِلهمْ] ﴿مصبحين﴾ أَي: نَهَارا [يُرِيد: فِي النَّهَار إِلَى الشَّام فِي ذهابكم إِلَى الشَّام، وإقبالكم بِالتِّجَارَة وترون مَا صنعت بهم]