Malik was asked about the meaning of his saying: There is no safar. He replied: The people of pre-Islamic Arabia used to make the month of safar lawful (for war). They made it lawful in one year and unlawful in another year. The Prophet ﷺ said: There is no safar.
عَنْ قَوْلِهِ لاَ صَفَرَ قَالَ إِنَّ أَهْلَ الْجَاهِلِيَّةِ كَانُوا يُحِلُّونَ صَفَرَ يُحِلُّونَهُ عَامًا وَيُحَرِّمُونَهُ عَامًا فَقَالَ النَّبِيُّ ﷺ لاَ صَفَرَ