كتاب الإيمان وشرائعه
Read the English translation first, with the original Arabic directly underneath.
It was narrated from Abu Hurairah that:
The Messenger of Allah [ﷺ] was asked: "Which deed is best?" "He said: Faith in Allah [SWT] and His messenger [ﷺ]."
الإِيمَانُ بِاللَّهِ وَرَسُولِهِ