Al-Baqarah 2:235 ولا جناح عليكم فيما عرضتم به من خطبة النساء او اكننتم في انفسكم علم الله انكم ستذكرونهن ولاكن لا تواعدوهن سرا الا ان تقولوا قولا معروفا ولا تعزموا عقدة النكاح حتى يبلغ الكتاب اجله واعلموا ان الله يعلم ما في انفسكم فاحذروه واعلموا ان الله غفور حليم ٢٣٥

And there is no sin on you if you make a hint of betrothal or conceal it in yourself, Allâh knows that you will remember them, but do not make a promise of contract with them in secret except that you speak an honourable saying according to the Islâmic law.¹ And do not consummate the marriage until the term prescribed is fulfilled. And know that Allâh knows what is in your minds, so fear Him. And know that Allâh is Oft-Forgiving, Most Forbearing.