Allah said,

﴿مَّن ذَا الَّذِى يُقْرِضُ اللَّهَ قَرْضًا حَسَنًا﴾

(Who is he that will lend Allah a handsome loan:) `Umar bin Al-Khattab said that this Ayah refers to spending in Allah's cause. It was also said that it pertains to spending on children. What is correct is that it is more general than that. So all those who spend in the cause of Allah with good intentions and a sincere heart, then they fall under the generality of this Ayah. This is why Allah the Exalted said in another Ayah:

﴿مَّن ذَا الَّذِى يُقْرِضُ اللَّهَ قَرْضًا حَسَنًا فَيُضَاعِفَهُ لَهُ﴾

(Who is he that will lend Allah handsome loan: then (Allah) will increase it manifold to his credit (in repaying),) and in another Ayah,

﴿أَضْعَافًا كَثِيرَةً﴾

(many times) (2:245), meaning, being handsome reward and tremendous provisions: Paradise on the Day of Resurrection. Ibn Abi Hatim recorded that `Abdullah bin Mas`ud said, "When this Ayah,

﴿مَّن ذَا الَّذِى يُقْرِضُ اللَّهَ قَرْضًا حَسَنًا فَيُضَاعِفَهُ لَهُ﴾

(Who is he that will lend Allah handsome loan: then (Allah) will increase it manifold to his credit (in repaying),) was revealed, Abu Ad-Dahdah Al-Ansari said, `O Allah's Messenger! Does Allah ask us for a loan' The Prophet said,

«نَعَمْ، يَاأَبَا الدَّحْدَاح»

(Yes, O Abu Ad-Dahdah.) He said, `Give me your hand, O Allah's Messenger,' and the Prophet placed his hand in his hand. Abu Ad-Dahdah said, `Verily, I have given my garden as a loan to my Lord.' He had a garden that contained six hundred date trees; his wife and children were living in that garden too. Abu Ad-Dahdah went to his wife and called her, `Umm Ad-Dahdah!' She said, `Here I am.' He said, `Leave the garden, because I have given it as a loan to my Lord, the Exalted and Most Honored.' She said, `That is a successful trade, O Abu Ad-Dahdah!' She then transferred her goods and children. The Messenger of Allah said,

«كَمْ مِنْ عَذْقٍ رَدَاحٍ فِي الْجَنَّةِ لِأَبِي الدَّحْدَاح»

(How plentiful are the sweet date clusters that Abu Ad-Dahdah has in Paradise!)'' In another narration, the Prophet said,

«رُبَّ نَخْلَةٍ مُدَلَّاةٍ، عُرُوقُهَا دُرٌّ وَيَاقُوتٌ، لِأَبِي الدَّحْدَاحِ فِي الْجَنَّة»

(How many a date tree that has lowered down its clusters, which are full of pearls and gems in Paradise for Abu Ad-Dahdah!)

﴿يَوْمَ تَرَى الْمُؤْمِنِينَ وَالْمُؤْمِنَـتِ يَسْعَى نُورُهُم بَيْنَ أَيْدِيهِمْ وَبِأَيْمَـنِهِم بُشْرَاكُمُ الْيَوْمَ جَنَّـتٌ تَجْرِى مِن تَحْتِهَا الاٌّنْهَـرُ خَـلِدِينَ فِيهَا ذَلِكَ هُوَ الْفَوْزُ الْعَظِيمُ - يَوْمَ يَقُولُ الْمُنَـفِقُونَ وَالْمُنَـفِقَـتُ لِلَّذِينَ ءَامَنُواْ انظُرُونَا نَقْتَبِسْ مِن نُّورِكُمْ قِيلَ ارْجِعُواْ وَرَآءَكُمْ فَالْتَمِسُواْ نُوراً فَضُرِبَ بَيْنَهُم بِسُورٍ لَّهُ بَابٌ بَاطِنُهُ فِيهِ الرَّحْمَةُ وَظَـهِرُهُ مِن قِبَلِهِ الْعَذَابُ - يُنَـدُونَهُمْ أَلَمْ نَكُن مَّعَكُمْ قَالُواْ بَلَى وَلَـكِنَّكُمْ فَتَنتُمْ أَنفُسَكُمْ وَتَرَبَّصْتُمْ وَارْتَبْتُمْ وَغرَّتْكُمُ الاٌّمَانِىُّ حَتَّى جَآءَ أَمْرُ اللَّهِ وَغَرَّكُم بِاللَّهِ الْغَرُورُ - فَالْيَوْمَ لاَ يُؤْخَذُ مِنكُمْ فِدْيَةٌ وَلاَ مِنَ الَّذِينَ كَفَرُواْ مَأْوَاكُمُ النَّارُ هِىَ مَوْلَـكُمْ وَبِئْسَ الْمَصِيرُ ﴾

(12. On the Day you shall see the believing men and the believing women -- their light running forward before them and in their right hands. Glad tidings for you this Day! Gardens under which rivers flow (Paradise), to dwell therein forever! Truly, this is the great success!) (13. On the Day when the hypocrites men and women will say to the believers: "Wait for us! Let us get something from your light!'' It will be said: "Go back to your rear! Then seek a light!'' So, a wall will be put up between them, with a gate therein. Inside it will be mercy, and outside it will be torment.) (14. (The hypocrites) will call the believers: "Were we not with you'' The believers will reply: "Yes! But you led yourselves into temptations, you looked forward to our destruction; and you doubted, and you were deceived by false hopes, till the command of Allah came to pass. And the deceiver deceived you in regard to Allah.'') (15. So, this Day no ransom shall be taken from you, nor of those who disbelieved. Your abode is the Fire. That is your protector, and worst indeed is that destination.)