Do causes increase and provision decrease, or is provision fixed and unchangeable, and causes are merely an act of worship and reliance upon God?

Sustenance (rizq) is of two types: The first is what Allah has known, and it does not change. The second is what He has decreed and informed the angels about, and this increases and decreases based on causes, such as maintaining kinship ties and an increase in lifespan through righteousness. The causes by which sustenance is obtained are predetermined by Allah, and the pursuit of sustenance is through work, supplication (du'a), reliance (tawakkul), and beneficence (ihsan).