The truest word spoken by an Arab (pre-Islamic) in poetry is this verse of Labid: "Behold! apart from Allah everything is vain."
عَنِ النَّبِيِّ ﷺ قَالَ أَشْعَرُ كَلِمَةٍ تَكَلَّمَتْ بِهَا الْعَرَبُ كَلِمَةُ لَبِيدٍ أَلاَ كُلُّ شَىْءٍ مَا خَلاَ اللَّهَ بَاطِلٌ