[It is that] you believe in Allāh and His Messenger and strive in the cause of Allāh with your wealth and your lives. That is best for you, if you only knew.
We mentioned a Hadith from `Abdullah bin Salam in that the Companions wanted to ask the Prophet of Allah about the best actions with Allah the Exalted and Most Honored, so they could practice them. Allah the Exalted sent down this Surah, including this Ayah,
(O you who believe! Shall I guide you to a trade that will save you from a painful torment) Allah then explained this great trade that will never fail, the trade that will earn one what he wishes and saves him from what he dislikes. Allah the Exalted said,
تُؤْمِنُونَ بِاللَّـهِ وَرَسُولِهِ وَتُجَاهِدُونَ فِي سَبِيلِ اللَّـهِ بِأَمْوَالِكُمْ وَأَنفُسِكُمْ ( ...you believe in Allah and His Messenger, and carry out jihad in His way with your riches and your lives....61:11) This verse refers to 'faith and jihad (struggle) in Allah's way with one's wealth and life' as a trade, because when man invests wealth in trade and works hard, he gains profit. Likewise, when man believes in Allah and invests his life and wealth in His cause, he incurs Allah's pleasure and attains the eternal blessings of the Hereafter, which is mentioned in the forthcoming verse that whoever carries out this trade, Allah will forgive his sins and provide him with dwellings in the Gardens of Eternity with all sorts of luxuries and comforts, as is mentioned by the Holy Prophet in explanation of 'pleasant dwellings'. Alongside the blessings of the Hereafter, the next verse promises some blessings of this world too:
Tazkirul Quran
Maulana Wahiduddin KhanOn ayahs 11–13
In trade, a man first invests and then receives a return on his investment. In the struggle for Faith also one has to invest his strength and his possessions. From this view point, this is also a sort of trade. But, one receives the profit from worldly trade in this world, while in the religion-oriented trade, one receives the profit with further additions only in the Hereafter.
Uthmani text of the Madinah mushaf (King Fahd Complex). Translation: Saheeh International. Tafsir via Quran.com.