In the present context, a person like this may be called an opportunist. The one who is always safe and secure and has no ideals and uncertainty of his brother's misfortune for his deeds, this is a deplorable character in Islam.
أبي هريرة رضي الله عنه أن رسول الله صلى الله عليه وسلم قال: "إن من شر الناس ذا الوجهين الذي يأتي هؤلاء بوجه وهؤلاء بوجه" (رواه البخاري 3304) ومسلم (2526.)
From Abu Hurairah radhiyallahuanhu has said Prophet sallallaahu alaihi wasallam say: "Truly the ugly ugly man is the person who has two faces present to them with their face, when they come to another with a different face" [HR. Bukhari no. 3304 Muslim no. 2526]
وقال النووي: هو الذي يأتي كل طائفة بما يرضيها فيظهر لها أنه منها ومخالف لضدها, وصنيعه نفاق ومحض كذب وخداع وتحيل على الاطلاع على أسرار الطائفتين ... قال: فأما من يقصد بذلك الإصلاح بين الطائفتين فهو محمود. انظر شرح النووي لصحيح مسلم (16/156)
Imam An-Nawawi Rahumahullah said, "The meaning of this two-faced person, who comes to a group by appearing to be on their side and opposite his opponent, but in the same way he also came to the group And do the same thing , He is nifak, lying, and deceiving and revealing the secrets of each group .... [Sharah Muslim 16/156]
قال الحافظ ابن حجر العسقلانى رحمه الله تعالى: أما معناه فقد قال القرطبي:. إنما كان ذو الوجهين شر الناس; لأن حاله حال المنافق, إذ هو متملق بالباطل وبالكذب, مدخل للفساد بين الناس (10/474)
Al-Hafidz Ibn Hajar Al-Asqalani rahimahullah said: "The two-faced meaning as described by Al-Qurthubi he says: indeed two-faced is as bad as mankind, its character as hypocritical, then he subtly carries the character of vanity and Lie, And In the blood of human destruction "[Fathul Bari. 10/474]
The Prophet not only denounced this double-faced, person as one who belongs to the ranks of the noble ones with Allah hug him also threaten them with hell! In this case, the Prophet sallallaahu 'alaihi wa sallam said, "Whoever has two faces in the world, then on the Day of Judgment he will be given two mouths of the fire of hell." (Abu Dawud and Ad-Darimi of Ammar bin Yasir)
Naudzu billah hopefully we are kept away by God from this bad trait, whose impact and influence will not only harm ourselves in others emerge naminah, ghibah, and unfair competition.
WA Madzhab Imam Ash-Shafi'i