Surah Al-Baqarah 2:235

وَلَا جُنَاحَ عَلَيْكُمْ فِيمَا عَرَّضْتُم بِهِۦ مِنْ خِطْبَةِ ٱلنِّسَآءِ أَوْ أَكْنَنتُمْ فِىٓ أَنفُسِكُمْ ۚ عَلِمَ ٱللَّهُ أَنَّكُمْ سَتَذْكُرُونَهُنَّ وَلَـٰكِن لَّا تُوَاعِدُوهُنَّ سِرًّا إِلَّآ أَن تَقُولُوا۟ قَوْلًا مَّعْرُوفًا ۚ وَلَا تَعْزِمُوا۟ عُقْدَةَ ٱلنِّكَاحِ حَتَّىٰ يَبْلُغَ ٱلْكِتَـٰبُ أَجَلَهُۥ ۚ وَٱعْلَمُوٓا۟ أَنَّ ٱللَّهَ يَعْلَمُ مَا فِىٓ أَنفُسِكُمْ فَٱحْذَرُوهُ ۚ وَٱعْلَمُوٓا۟ أَنَّ ٱللَّهَ غَفُورٌ حَلِيمٌ

There is no blame upon you for that to which you [indirectly] allude concerning a proposal to women or for what you conceal within yourselves. Allāh knows that you will have them in mind. But do not promise them secretly except for saying a proper saying. And do not determine to undertake a marriage contract until the decreed period reaches its end. And know that Allāh knows what is within yourselves, so beware of Him. And know that Allāh is Forgiving and Forbearing.

Translation: Saheeh International

Tafsir

You would not be at fault regarding the proposal with the intention of marriage you present offer or hide in your hearts during the waiting period to women whose spouses have died such as men saying ‘How beautiful you are!’ or ‘Who could find one like you?’ or ‘How many a man must desire you!’. …

Excerpt from Tafsir al-Jalalayn, commentary on 2:235, via Quran.com. The reader has the full commentary and 9 more tafsirs.