💯 Miscellaneous benefits from Yemen

BENEFIT 17: THE عدد AND معدود OPPOSE IN GENDER (from 3 - 10) EXCEPT IN TWO CASES Grammar Rule: The عدد (number) from 3 - 10 opposes the مَعْدُود (the thing counted) in terms of gender; if the معدود is masculine, the عدد will be feminine, and vice versa. For example: ثلاث سيارات ثلاثة كتب However, the are two exceptions to this rule: The first exception: If the عدد is mentioned without the معدود, you have two options: a- to implement the above rule or b- to ignore the rule For example: we can implement the rule and say: صُمْ سِتَّةً "fast six (days)!" Or we can ignore the rule and say: صُمْ سِتًّا "fast six (days)!" The second exception: If the معدود is mentioned before the عدد, we can also exercise the above two options. For example: We can implement the rule and say: جاء رجالٌ ستَّةٌ Or we can ignore the rule and say: جاء رجالٌ ستٌّ ______ The above benefit was taken from one of Sheikh Abū Bilāl's Bulūgh Al-Marām classes; the chapter concerning voluntary fasts; ḥadīth Abū Ayyūb in Muslim pertaining to fasting the six days of Shawwāl: ((من صام رمضان ثم أتبعه ستا من شوال كان كصيام الدهر)) ''Whoever fasts Ramaḍhān, then follows it with (fasting) six from Shawwāl, it is as though he has fasted the whole year.'' MAS'ALAH: Why did the Prophet صلى الله عليه وسلم say ست instead of ستة while the معدود is masculine (أيام)❓ After reading the above benefit, I hope you are able to answer this question