ما عطف من طرفيها
what is bent from its two ends
والهاء في الواحد عوض من الواو
and the 'ha' in the singular is a substitute for the 'waw'
والنسبة إليها سيوى
and the attribution to it is 'sayawa'
كان رؤبة بن العجاج يهمز سية القوس وسائر العرب لا يهمزونها
Ru'bah ibn al-'Ajjaj used to pronounce the tip of the bow with a hamza, while the rest of the Arabs did not.
يقال هو في سي رأسه، وفي سواء رأسه، إذا كان في النعمة
It is said, 'He is in the 'siyy' of his head, and in the 'sawā'' of his head,' if he is in prosperity.
وقد يفسر سي رأسه عدد شعره من الخير
And 'siyy ra'sihi' may be interpreted as the number of his hairs, signifying abundance and good fortune.
كأنه (1) خاضب بالسي مرتعه
As if his grazing place was dyed with 'siyy' (abundance/well-being)
والسي: أرض من أراضي العرب، وقد تكون المفازة
And 'as-siyy' is a land of the lands of the Arabs, and it may be a desolate plain.
والسيان: المثلان، الواحد سى
And 'as-siyān' are the two alike, the singular is 'siyy'
فإياكم وحية بطن واد * همو الناب ليس لكم بسى
Beware of the snake in the belly of a valley; its fang is not like you (i.e., not comparable to you).
يريد تعظيمه
He means its greatness/importance.
ولا سيما أخوك، أي ولا سى الذى هو أخوك
And not especially your brother, meaning 'and not like that which is your brother'.
إن شئت جعلت ما بمنزلة الذى وأضمرت مبتدأ ورفعت الاسم الذى تذكره لخبر المبتدأ
If you wish, you make 'mā' in the position of 'alladhī' (which) and you imply a subject and raise the noun you mention as the predicate of the implied subject.
وإن شئت جررت ما بعده على أن تجعل ما زائدة، وتجر الاسم بسى ; لان معنى سى معنى مثل
And if you wish, you may put the following noun in the genitive case by making 'mā' superfluous, and put the noun in the genitive with 'siyy', because the meaning of 'siyy' is the meaning of 'mithl' (like).
ألا رب يوم لك منهن صالح * ولا سيما يوم بدارة جلجل
Perhaps there is a good day for you among them, and especially the day of Badrat Juljul.
وتقول: اضربن القوم ولا سيما أخيك، أي ولا مثل ضربه أخيك
And you say: Strike the people, and especially your brother, meaning 'and not like the striking of your brother'.
وإن قلت: ولا سيما أخوك، أي ولا مثل الذى هو أخوك، تجعل ما بمعنى الذى وتضمر هو وتجعله مبتدأ وأخوك خبره
And if you say: 'Wa lā siyyamā akhūk,' meaning 'and not like that which is your brother,' you make 'mā' mean 'alladhī' and imply 'huwa' (he) and make it a subject and 'akhūk' its predicate.
إن فلانا كريم ولا سيما إن أتيته قاعدا، فإن " ما " هاهنا زائدة لا تكون من الاصل، وحذف هنا الاضمار، وصار ما عوضا منه، كأنه قال: ولا مثله إن أتيته قاعدا
So-and-so is generous, and especially if you come to him while sitting. Here, 'mā' is superfluous and not from the root; the implied pronoun is omitted, and 'mā' becomes a substitute for it, as if it were said: 'and not like him if you come to him while sitting'.