It is He who sent down tranquillity into the hearts of the believers.
Quran 48:4
Quran 48:4

“It is He who sent down tranquillity into the hearts of the believers.”

Allah is the One Who sent down stability and tranquility into the hearts of the believers so that they increase in faith over and above their faith. To Allah alone belongs the forces of the heavens and the earth, He supports with them whoever of His servants He wishes.

The plain meaning, from Al-Mukhtasar fi at-Tafsir

The full passage

هُوَ ٱلَّذِىٓ أَنزَلَ ٱلسَّكِينَةَ فِى قُلُوبِ ٱلْمُؤْمِنِينَ لِيَزْدَادُوٓا۟ إِيمَٰنًا مَّعَ إِيمَٰنِهِمْ ۗ وَلِلَّهِ جُنُودُ ٱلسَّمَٰوَٰتِ وَٱلْأَرْضِ ۚ وَكَانَ ٱللَّهُ عَلِيمًا حَكِيمًا

It is He who sent down tranquility into the hearts of the believers that they would increase in faith along with their present faith. And to Allah belong the soldiers of the heavens and the earth, and ever is Allah Knowing and Wise.

Quran 48:4The Arabic it was clipped from
The explanation

What does Quran 48:4 mean?

Surah al-Fath was revealed around the treaty of Hudaybiyyah — an agreement that looked to many of the companions like a defeat, and is called a clear victory here. The word for what was sent down, sakinah, is a settling: not the removal of the difficulty but a steadiness inside it. And the stated purpose is growth — that they might increase in faith along with the faith they already had.

Written from Al-Mukhtasar fi at-Tafsir

Where it sits