The way we observe the Contact Prayers has been guarded and preserved by God even though He didn't state all details in Quran. Quran teaches that the Contact Prayers and all other worshiping practices for Submitters were in existence before Quran and were initially delivered and practiced by Abraham:
[2:125] We have rendered the shrine (the Ka`aba) a focal point for the people, and a safe sanctuary. You may use Abraham's shrine as a prayer house. We commissioned Abraham and Ismail: "You shall purify My house for those who visit, those who live there, and those who bow and prostrate."
[2:127] As Abraham raised the foundations of the shrine, together with Ismail (they prayed): "Our Lord, accept this from us. You are the Hearer, the Omniscient.
[2:128] "Our Lord, make us submitters to You, and from our descendants let there be a community of submitters to You. Teach us the rites of our religion, and redeem us. You are the Redeemer, Most Merciful.
[2:129] "Our Lord, and raise among them a messenger to recite to them Your revelations, teach them the scripture and wisdom, and purify them. You are the Almighty, Most Wise."
[2:130] Who would forsake the religion of Abraham, except one who fools his own soul? We have chosen him in this world, and in the Hereafter he will be with the righteous.
[2:132] Moreover, Abraham exhorted his children to do the same, and so did Jacob: "O my children, GOD has pointed out the religion for you; do not die except as submitters."
[2:133] Had you witnessed Jacob on his death bed; he said to his children, "What will you worship after I die?" They said, "We will worship your god; the god of your fathers Abraham, Ismail, and Isaac; the one god. To Him we are submitters."
Abraham, his children, and descendants of his grandchildren (Jacob's children) had served as witnesses to pass down and preserve the rites of our religion including the Contact Prayers. The righteous from among their communities had played the same exact role to pass down and protect the rites of our religion as originally delivered by Abraham. Afterwards, the Contact Prayers started to fade away (19:58-59). A new warner and a prophet was sent by God. Muhammad delivered Quran which confirms all the existing rituals since Abraham and commands him to be a strict follower of the religion of Abraham (16:123). The word "Millat," used in 16:123 means "what a religion brings" in the Arabic language. Muhammad obeyed the command and followed the rites that had been practiced since Abraham:
[16:123] Then we inspired you (Muhammad) to follow the religion (Millat) of Abraham,* the monotheist; he never was an idol worshiper.
We learn that our Contact Prayers were only confirmed in Quran. The elements that are dealt with in Quran are limited to the tone we use for prayer (17:110), the basic steps of ablution and dry ablution (5:6), shortening the prayers and praying at war (4:101-102), praying under unusual circumstances (2:239), the times or names of our five daily contact prayers (24:58, 17:78, 2:238, 11:114), how we must observe them regularly and within their designated time frames (70:34, 4:103), and the command of giving the utmost importance to the Friday Congregational Contact Prayer (62:9-11). Any details concerning our Contact Prayers that are not mentioned in Quran have been guarded and preserved and this is logically why they didn't get to be repeated in Quran.
Muhammad, the righteous from among his community and their descendants served as witnesses to pass down and guard our rites including our Contact Prayers. However, history repeated itself. Few hundred years after Muhammad's departure, Muslims started to inject their idol worshiping beliefs into the Contact Prayers, and they have been explicitly violating 72:18 and 7:29 since then, dedicating their Contact Prayers to their idols besides God. Following the unchangeable divine system of purifying and preserving our rites, God has sent another messenger, Rashad, after a period of time, who purified and reconfirmed our Contact Prayers to be devoted absolutely to God alone (5:19, 33:7, 3:81).
While we are promoting God's message to humanity and inviting the world to abandon idolatry, worship God alone, and follow the preserved and authenticated word of God in Quran, Satan is at work to nullify our efforts. We have been hearing his whispers and witnessing his desperate attempts of spreading doubts about the manner in which we observe our daily and Friday Contact Prayers. He has been also disputing the number, the names, the times, and the order of our daily contact prayers.
Instead of feeling appreciative, content, and blessed we received and witnessed a messenger who purified and confirmed Quran, and put us back on the monotheistic path, some have been distracted by our ardent enemy. Despite the straightforward verses that spell out God's system of inheriting and preserving our rites, some have been caught up in the Satanic illusion that God would send a messenger to mislead the believers and pass down some wrong teachings in regard of the Contact Prayers- a precedent that DOES NOT exist in Quran. NO where in Quran we find a single example of a messenger who misguided the people or gave them wrong religious practices when their redemption relies on such practices. To the contrary, God assures the believers that His messengers are sent as a mercy to lead them out of darkness, assure their hearts, and teach them the rites to purify and redeem their souls (2:150-151, 14:4-5, 2:129, 3:164, 62:2, 9:103).
Believing in Quran mandates the belief in the words stated by God to teach us the above system of delivery, practice, inheritance, preservation, and confirmation of our rites through His messengers, His scriptures, and His witnesses. This system is a part of the complete, and perfect details of Quran. Ignoring this system, chosen and clarified by God, and hanging on personal wishes to find all the details of Contact Prayers in Quran or to argue about them after receiving God's guidance reflects our disbelief in the Quran, the lack of trust in its divinity, or the lack of trust in God and His systems.
We play a significant role guarding against any attempts to abrogate the system of our Contact Prayers. Since we have witnessed a messenger confirming and delivering our Contact Prayers, we cannot escape the service of being witnesses among the people. Being a witness among the people is an active duty and an obligation to set the right precedent and deliver the truth. We are obligated to hand the correct prayers as preserved by God to others if we are going to serve as legitimate and truthful witnesses. The following verses deliver a powerful lesson about the witnesses playing an active role in the divine plan of preserving the rites:
Abraham: Original Messenger of Islam [22:78] You shall strive for the cause of GOD as you should strive for His cause. He has chosen you and has placed no hardship on you in practicing your religion - the religion of your father Abraham. He is the one who named you "Submitters" originally. Thus, the messenger shall serve as a witness among you, and you shall serve as witnesses among the people. Therefore, you shall observe the Contact Prayers (Salat) and give the obligatory charity (Zakat), and hold fast to GOD; He is your Lord, the best Lord and the best Supporter.
Abolition of Bigotry and Prejudice
[2:142] The fools among the people would say, "Why did they change the direction of their Qiblah?" Say, "To GOD belongs the east and the west; He guides whoever wills in a straight path."
[2:143] We thus made you an impartial community, that you may serve as witnesses among the people, and the messenger serves as a witness among you. We changed the direction of your original Qiblah only to distinguish those among you who readily follow the messenger from those who would turn back on their heels. It was a difficult test, but not for those who are guided by GOD. GOD never puts your worship to waste. GOD is Compassionate towards the people, Most Merciful.
[3:53] "Our Lord, we have believed in what You have sent down, and we have followed the messenger; count us among the witnesses."