فَاضِلًا عَنْ مَسْكَنِهِ، وَمَا لَا بُدَّ مِنْهُ
Translation: With means beyond the person’s home and indispensable necessities.
Fāḍilan ʿan maskanihi means that financial ability is measured beyond the home required for living. Wa-mā lā budda minhu extends this idea to other indispensable needs.
A necessity is not automatically treated in the same way as surplus disposable wealth.