57:10
وَمَا لَكُمْ أَلَّا تُنفِقُوا۟ فِى سَبِيلِ ٱللَّهِ وَلِلَّهِ مِيرَٰثُ ٱلسَّمَٰوَٰتِ وَٱلْأَرْضِ ۚ لَا يَسْتَوِى مِنكُم مَّنْ أَنفَقَ مِن قَبْلِ ٱلْفَتْحِ وَقَٰتَلَ ۚ أُو۟لَٰٓئِكَ أَعْظَمُ دَرَجَةًۭ مِّنَ ٱلَّذِينَ أَنفَقُوا۟ مِنۢ بَعْدُ وَقَٰتَلُوا۟ ۚ وَكُلًّۭا وَعَدَ ٱللَّهُ ٱلْحُسْنَىٰ ۚ وَٱللَّهُ بِمَا تَعْمَلُونَ خَبِيرٌۭ
And why do you not spend in the cause of Allah while to Allah belongs the heritage of the heavens and the earth? Not equal among you are those who spent before the conquest [of Makkah] and fought [and those who did so after it]. Those are greater in degree than they who spent afterwards and fought. But to all Allah has promised the best [reward]. And Allah, with what you do, is Acquainted.
Translation · Saheeh International
Tafsir
Ibn Kathīr (abridged)
Ordering Faith and encouraging spending
Allah the Exalted and Blessed orders having perfect faith in Him and in His Messenger, and that one should persist on this path adhereing firmly to it. Allah encourages spending from what He has made mankind trustees of, the wealth that you - mankind - have, that He has lent you. This wealth was in the hands of those before you and was later transferred to you. Therefore, O mankind, spend as Allah commanded you from the wealth that He entrusted to you for His obedience. Otherwise, He will hold you accountable and punish you for your ignoring what He ordained on you in this regard. Allah's statement,
مِمَّا جَعَلَكُم مُّسْتَخْلَفِينَ فِيهِ
(of that whereof He has made you trustees.), indicates that you - mankind -- will surrender this wealth to someone else. In this case, those who will inherit from you might obey Allah with their wealth, and thus acquire more happiness than you on account of what Allah has granted them. They might disobey Allah, and in this case you will have helped them commit evil and transgression. Imam Ahmad recorded that `Abdullah bin Ash-Shikhkhir said, "I came to Allah's Messenger ﷺ as he was reciting and saying,
أَلْهَـكُمُ التَّكَّاثُرُ
يَقُولُ ابْنُ آدَمَ: مَالِي مَالِي، وَهَلْ لَكَ مِن مَالِكَ إِلَّا مَاأَكَلْتَ فَأَفْنَيْتَ، أَوْ لَبِسْتَ فَأَبْلَيْتَ، أَوْ تَصَدَّقْتَ فَأَمْضَيْتَ؟»