The Messenger of Allah ﷺ said: The prayer of a person who does not perform ablution is not valid, and the ablution of a person who does not mention the name of Allah (in the beginning) is not valid. (Using translation from Abū Dāʾūd 101)
قَالَ رَسُولُ اللهِ ﷺ لَا وُضُوءَ لِمَنْ لَمْ يَذْكُرْ اسْمَ اللهِ عَلَيْهِ