Arabic is one of the major languages of world. Nouns showing numbers in Arabic are of three kinds: Singular, Dual and Plural. The Singulars refer to only one thing for which they were made. The dual conceptualizes that the particular  word denotes two things. The plurals give meanings to more than two (dual). The Arabs are of the habit of using different words for a thing on account of its minor differences. For examples, The Arabic equivalent of Sword is 'saif' (سیف).  The Arabs use different words for the same thing in case of minor changes found in it.  If the sword has shining brightness, they call it 'seiquel' ( صیقل).  If it is sharp enough, they call it (صارم), and if the sword's cutting character is prominent, they call it 'Qatey' (قاطع).  The Arabs use several singular words for a singular thing due to its changing conditions or qualities.  The same formula is applied to the things indicating duality (تثنیۃ ). This paper presents the Arabic duals which refer to day and night (اللیل والنھار). We are going to present twenty six Arabic duals in this regard to show the vastness of Arabic vocabulary in it dual forms.