وَعَلمَاتٍAnd landmarks,meaning, signs like great mountains and small hills, and so on, things that land and sea travelers use to find their way if they get lost.وَبِالنَّجْمِ هُمْ يَهْتَدُونَand by the stars (during the night), they (mankind) guide themselves.meaning, in the darkness of the night.This was the opinion of Ibn Abbas.Worship is Allah's Right Then Allah tells us of His greatness, and that worship should be directed to Him alone, not to any of the idols which do not create but are rather themselves created.Thus He says,أَفَمَن يَخْلُقُ كَمَن لاَّ يَخْلُقُ أَفَل تَذَكَّرُونَ