Surah Al Furqan Tafseer

وَالَّذِينَ إِذَا أَنفَقُوا لَمْ يُسْرِفُوا وَلَمْ يَقْتُرُوا

And those who, when they spend, are neither extravagant nor stingy...

They are not extravagant, spending more than they need, nor are they miserly towards their families, not spending enough on their needs. But they follow the best and fairest way. The best of matters are those which are moderate, neither one extreme nor the other.

وَكَانَ بَيْنَ ذَلِكَ قَوَامًا

but are in a just balance between them.

This is like the Ayah,

وَلَا تَجْعَلْ يَدَكَ مَغْلُولَةً إِلَى عُنُقِكَ وَلَا تَبْسُطْهَا كُلَّ الْبَسْطِ

And let not your hand be tied to your neck, nor stretch it forth to its utmost reach. (17:29