You ask us to follow a Bible practice when the Qur'an does not prohibit it. But the Jews are told to judge what they do BY THE QUR'AN which they reject!
When the Qur'an says it is a watcher over the remaining truth in the Bible, this means we are to reject those things which the Qur'an does not substantiate.
The Jews and you make good company!
5:41 O Messenger! Let not those grieve you who run to disbelief, saying, “We believe,” with their mouths, while their hearts have no faith. And grieve not about those Jews who listen for the sake of fabricating lies. They listen and go to their people who have never met with you. Then they distort the words out of context and tell others to accept only a part and reject a part. If God intends trial for anyone, you have no authority in the least for him against God. God does not purify the hearts of such people. For them there is disgrace in this world and an awful punishment in the Hereafter.
5:42 They are upholders of falsehood and they make wealth by unfair means. They are bribed into spying. If they come to you asking to judge among them, the choice to accept or reject their request is yours. You have the right to disclaim jurisdiction since they have not yet accepted the Qur’an and they have the Torah. If you disclaim jurisdiction they cannot harm you at all. However, if you decide to judge among them, do so equitably. God loves the equitable.
5:43 Why do they ask you to act as a judge among them when they have the Torah, containing God’s law and they disregard it? They are not believers.
5:44 We did send down the Torah containing guidance and a light. By it the Prophets who always sincerely submitted to God, judged the Jews. And the rabbis and the priests judged according to God’s scripture as they were commanded to observe. To them was entrusted the protection of God’s Book, and they were witnesses to it. So, fear not people, but fear Me and do not trade away My revelations for petty gains. And whoever fails to judge or rule by what God has revealed, such are the disbelievers (‘Kafiroon’).
5:45 For them (Jews), We had decreed in the Torah: Life for life, eye for eye, nose for nose, ear for ear, tooth for tooth, and equal injury for injury. But if one forgoes retaliation by way of charity, it will absolve his imperfections. And whoever fails to judge or rule by what God has revealed, such are wrongdoers (‘Zalimoon’). [Exodus 21:23. That was a Mosaic law specific to the Israelites. The Final revelation of God, the Qur’an has updated laws for all humanity for all times. Incidentally, Exodus in the Bible as seen today leaves no room for forgiveness of the mentioned offenses]
5:46 And after them We caused Jesus, son of Mary, to follow in their footsteps, confirming (the remaining truth in) what was revealed before him. We gave him the Gospel in which there was guidance and a light, and it confirmed the (truth in) what was revealed before it in the Torah, a guidance and admonition to those who wished to live upright. [2:101, 3:78]
5:47 Let the People of the Gospel judge by what God has revealed therein. And whoever fails to judge or rule by what God has revealed, are drifters from the right path (‘Fasiqoon’).
5:48 (O Messenger) We have sent to you this Divine Writ, setting forth the truth. It confirms the remaining truth in the earlier scriptures since it is a Watcher over them. So, judge between them by what God has revealed, and do not follow their desires diverging from the truth that has come to you. For each community among you We have appointed certain evolving trends and a traced-out way. If God had willed, He could have made you all one single community. But He decided to let you test yourselves by what (potentials) He has granted you. So, outdo one another in doing good to the society. To God you will all return, and He will then make you understand wherein you differed. [2:101, 2:148, 3:78, 21:92-93, 23:52. Muhaimin = Watcher. Shari’ah = Evolving trends of a community = Rites. Minhaaj = A traced-out way = A set of laws. ‘min-al-kitab’ = From or remaining from the scripture]
5:49 So judge between them by what God has revealed. And do not follow their vain desires. Beware of them, lest they divert you from some of what God has revealed to you. If they turn away from the truth, be assured that God has decided to chastise them for some of their crimes. A great many people drift away from the right path.
5:50 Do they seek judgment of the Days of Ignorance? But who can give better judgment than God, for a people who have attained conviction in the truth?