When Safiyyah(RA) was captured by the Prophet (SAW), Bilal(RA) came with her and another woman and led them past some of the slain Jews. That woman cried out, struck her face and poured dust on her face after seeing the corpses.When Prophet(SAW) saw her, he said, "Take this she-devil away from me!". What was the reason he said this to that woman? Can anyone answer please?
There is no explanation of why the Prophet ﷺ ordered them to take that woman away from him as the hadith is not considered authentic by any means.
The long hadith you are referring to was documented by Al-Tabari in his book History of the Prophets and Kings is partially quoted below for reference:
حدثنا ابن حميد، قال: حدثنا سلمة، عن ابن إسحاق، قال ولما فتح رسول الله صلى الله عليه وسلم القموص حصن ابن أبي الحقيق، أتي رسول الله بصفية بنت حيي بن أخطب، وبأخرى معها، فمر بهما بلال وهو الذي جاء بهما على قتلى من قتلى يهود، فلما رأتهم التي مع صفية صاحت وصكت وجهها، وحثت التراب على رأسها، فلما رآها رسول الله، قال
أغربوا عني هذه الشيطانة
وأمر بصفية، فحيزت خلفه، وألقي عليها رداؤه، فعرف المسلمون أن رسول الله صلى الله عليه وسلم قد اصطفاها لنفسه، فقال رسول الله صلى الله عليه وسلم لبلال، فيما بلغني حين رأى من تلك اليهودية ما رأى
أنزعت منك الرحمة يا بلال حيث تمر بامرأتين على قتلى رجالهما
وكانت صفية قد رأت في المنام وهي عروس بكنانة بن الربيع بن أبي الحقيق، أن قمرا وقع في حجرها، فعرضت رؤياها على زوجها، فقال: ما هذا إلا أنك تمنين ملك الحجاز محمدا، فلطم وجهها لطمة اخضرت عينها منها، فأتي بها رسول الله صلى الله عليه وسلم وبها أثر منها، فسألها ما هو فأخبرته هذا الخبر
— NOTE: My own translation, so treat with care:
It was narrated by Ibn Humaid that he said that Salama said through Ibn Is-hāq: When the Prophet ﷺ
entered the fortress of Ibn Abi al-Huqayq, the Prophet ﷺ called for Safiyya bint Huyayy ibn Akhtab and another woman [her cousin]. Bilal, while taking them over to the Prophet, took a path that had some of the slain Jews, the woman with Safiyya screamed, struck her face, and poured dust over her head. When the Prophet ﷺ saw her [the woman with Safiyya], he said:
Take this devil away from me.
Then he [the Prophet] made Safia behind him and covered her with his gown. This is when the Muslims realized that he had chosen Safiyya for himself. The Prophet ﷺ then addressed Bilal, from what I was told about what he saw the woman do, and said:
Was mercy removed [from your heart], O' Bilal, that you pass with the two women by their slain men?
Safiyya had seen in a dream when she was the bride of Kināna ibn al-Rabī' ibn Abu al-Huqayq [her second husband, who died in the Battle of Khaybar], that a moon was dropped into her lap. She told her husband of the dream, and he said "This means nothing other than you are wishing for the King of Hijāz, Mohammad. He then slapped her face a slap from which one of her eyes turned green. When she [Safiyya] was brought to the Prophet ﷺ, she still had some traces of it [the slap]. The Prophet ﷺ asked her what that was, and she told him the story.
This hadith was documented in several other books, but mostly history or autobiography books, rather than books of hadith. The classification of all versions are either weak, very weak, or fabricated.
This version of the hadith is classified as very weak due to Mohammad ibn Humayd ibn Hayyān al-Tamīmi. The narration chain for this hadith is Salama ibn al-Fadl » Mohammad ibn Is-hāq » Mohammad ibn Humayd al-Tamīmi » Moḥammad ibn Jarīr al-Tabari. Ibn Humayd's hadiths are forsaken due to him being rejected by several scholars (e.g., 'Abdur-Rahmān ibn Yūsuf ibn Khirāsh Abu Hatim ar-Rāzi, Abu Zur'ā ar-Rāzi, Al-Fadl ibn al-'Abbās, Al-Nasā'i, Ibn Ya'qūb al-Juzajani, Is-hāq ibn Mansūr, Mohammad ibn Is-hāq ibn Khuzaima, Sālih ibn Mohammad Jazara, and others) as either not being trustworthy, making mistakes in narrations, lying, or any combination thereof.
For the sake of mentioning other opinions about Ibn Humaid, some scholars considered him weak but without further elaborations (e.g., Ad-Dāraqutni, Ibn Hajar, Adh-Dhahabi, and Al-Bukhāri), other scholars considered some of his hadiths acceptable — depending on whom said hadiths were narrated through — (e.g., Ibn Hibbān and Ibn Hanbal), while others considered him acceptable at large (e.g., Abu Ya'lā, Yahya ibn Ma'īn, Ja'far ibn Yamīn at-Tayālisi, Mohammad ibn Yahyā adh-Dhohli).