It is related that when Prophet Dawud (AS) supplicated, he would say, “Oh Allah, the One who provides sustenance for baby crow in it's nest….”
When the crow chick first hatches from it's egg, it appears white (and featherless). Hence, the (parent) crow does not recognize the chick and due to the difference between their colors, he abandons it. Out of His Generosity, Allah then sends to it a type of worm that is attracted to the smell of it's beak and crawls over it. The chick devours it and is sustained by this type of worm until it grows and it's black feathers grow out. At this, the parent crows recognize him and return to him. No one has the power to control this except Allah:
“Is there any creator other than Allah who provides for you?” [Quran 35:3]
“And there is no creature on earth but that upon Allah is its provision, and He knows it's place of dwelling and place of storage. All is in a clear register.” [Quran 11:6]
“Or who is it that could be an army for you to aid you other than the Most Merciful? The disbelievers are not but in delusion. Or who is it that could provide for you if He withheld His provision? But they have persisted in insolence and aversion.” [Quran 67:20,21]
Oh Allah, do not withhold your provision from us!
When people go out in search of their sustenance, this is a method of seeking the means (sabab). But one must know with certainty that no one provides except Allah. And the greatest of all provision is Jannah, as Allah has called it 'rizq' in His Words.
Therefore, every time you are granted something of this worldly life, anticipate that which is greater (Jannah)!
(Know that) Allah is asked for that which is small and that which is plenty. He is asked for that which is great and that which is insignificant. It is related in some traditions that Allah told Musa , 'Oh Musa, ask Me even for the salt for your food, ask Me for the food for your animal and ask me for the lace of your shoes.' For that which occurs only happens if The One and Only One permitted it to happen.