Is there anyone who will make Allah a generous loan so that He can multiply it for him many times over? Allah both restricts and expands. And you will be returned to Him. (Surat al-Baqara, 2:245)
Allah grants spiritual and material abundance to those who believe in Him and who obey Him wholeheartedly. He removes the difficulties they face. Upon encountering any hardship, trouble, or sickness, believers take refuge only in Allah. As a reward for this, Allah eases their tasks while making things difficult for unbelievers.
The Qur'an provides many examples about this issue. For instance, Prophet Musa (as) and the Children of Israel were forced to leave Egypt due to Pharaoh's violence. However, Pharaoh followed them. During this flight, the Children of Israel, who were caught between Pharaoh's army and the sea, thought that they were finished. Yet, Allah answered Prophet Musa's (as) call, divided the waters, and made a dry path so they could escape. Allah also destroyed Pharaoh and his army, and made the Children of Israel their inheritors.
This was also a manifestation of the following situation: “Those who make pilgrimage in the Way of Allah will find many places of refuge on Earth and ample sustenance. If anyone leaves his home, making pilgrimage to Allah and His Messenger, and death catches up with him, Allah will reward him. Allah is Ever-Forgiving, Most Merciful.” (Surat an-Nisa', 4:100) No doubt, Allah's promise has always been true—and will remain so—for His faithful servants. One verse reads:
Your Lord expands the provision of anyone He wills and restricts it. He is aware of and sees His servants. (Surat al-Isra', 17:30)