"So prostrate to Allah," meaning: pray to Allah. "And worship," that is: and worship Him and do not associate anything with Him.
Muhammad said: Samidun means those who are distracted/playful, and it is a dialect of Yemen.
﴿فاسجدوا لله﴾ فصلوا لله ﴿واعبدوا﴾ أَي: واعبدوه وَلَا تُشْرِكُوا بِهِ شَيْئا.
قَالَ محمدٌ: سامدون مَعْنَاهُ لاهون وَهِي لُغَة الْيمن.
