'Umar Ahmad ibn al-Khattab narrated from the Prophet (saws) said, "If you were to rely on Allah as He truly should be relied upon, He would provide for you as He provides for the birds: they go out in the morning hungry and return in the evening replete."
Imam Ahmad (1:30,52), At-Tirmidhi (2344)
"Whoever has taqwa of Allah- He will give him a way out and provide for him from where he does not expect. Whoever puts his trust in Allah - He will be enough for him." (Surah Talaq)
It has been narrated from him (saws) that he used to say in his supplication:
"O Allah, I ask you for true reliance upon you," and that he used to say:
"O Allah, make me of those who have replied upon You and so You sufficed them."
Ibn Abi-d-Dunya said, "It has reached me that one of the wise people said, 'Reliance has three degrees, first: giving up complaining; second: contentment; third: love. Giving up complaining is the degree of steadfastness. Contentment is the tranquility of the heart towards that which is decreed for one, and that is higher than the former. Love is that one's love is for that which Allah does with one. The first is the degree of those who do without (zahidoon). The second is that of the truthful (Saadiqoon). The third is that of the messengers."