Surah Al-Hujurat 49:14

۞ قَالَتِ ٱلْأَعْرَابُ ءَامَنَّا ۖ قُل لَّمْ تُؤْمِنُوا۟ وَلَـٰكِن قُولُوٓا۟ أَسْلَمْنَا وَلَمَّا يَدْخُلِ ٱلْإِيمَـٰنُ فِى قُلُوبِكُمْ ۖ وَإِن تُطِيعُوا۟ ٱللَّهَ وَرَسُولَهُۥ لَا يَلِتْكُم مِّنْ أَعْمَـٰلِكُمْ شَيْـًٔا ۚ إِنَّ ٱللَّهَ غَفُورٌ رَّحِيمٌ

The bedouins say, "We have believed." Say, "You have not [yet] believed; but say [instead], 'We have submitted,' for faith has not yet entered your hearts. And if you obey Allāh and His Messenger, He will not deprive you from your deeds of anything. Indeed, Allāh is Forgiving and Merciful."

Translation: Saheeh International

Tafsir

The Bedouins — a group of men from among the Banū Asad — say ‘We believe’ we affirm the truth in our hearts. Say to them ‘You do not believe; but rather say “We have submitted” we are outwardly compliant; for faith has not yet entered into your hearts’ hitherto; however it is expected of you. …

Excerpt from Tafsir al-Jalalayn, commentary on 49:14, via Quran.com. The reader has the full commentary and 9 more tafsirs.