As-Salaam alaikum,
Prophetic Traditions which speak about the guarantee of sustenance for every creature are many. For example:--

(1) In a hadith narrated by Abu Sa'id al-Khudri, may Allah be pleased with him, the Prophet, Sallallahu alaihi Wasallam, said:

''If anyone of you were to flee from his sustenance, it would pursue him just as
death pursues him.'' (Haythami, Mujma'al-zawa'id; Tabarani, al-Mu'jam al-awsat).

(2) The Prophet (also) said, speaking on behalf of our Lord: ''O Son of Adam, disengage yourself
for My worship and I will fill your heart with wealth and relieve you of poverty. If you do not,
your work will be the death of you.'' (Tirmidhi, Ibn Majah and Ahmad)

(3) The Prophet, Sallallahu alaihi Wasallam, also said: ''Whoever is concerned with the Hereafter,
Allah will cause him to feel rich, He will aid him and will subjugate the the world for his use.
Whoever is concerned with this life, Allah will lead him to believe poverty is inescapable; He
will not aid him and He will not give him anything of this world except what he has been apportioned.''
(Tirmidhi and Ibn Majah).

At this juncture, it will be appropriate to quote Sayyadi Harith Ibn Asad al-Muhasibi (165 A.H-243 A.H), may Allah be Merciful to him, who asked his master how doubt finds its way into people's mind/hearts when Allah has guaranteed us our sustenance. He responded:--

''It is for 2 reasons: from having too little spiritual knowledge and from not having a
good opinion of the Lord.''


I asked him if there is anything else. He said, ''Yes, Allah has promised people their sustenance and has guaranteed
it for them. However, He has not disclosed the times when it comes in order to test the people of intelligence. If this
was not so, all the believers would enjoy the spiritual states of contentment, patience and reliance... and this is why
servants are at different stations of spirituality. Some are at peace, some are in constant motion, some are angry and
some are anxious. The level of certainty (yaqin) they achieve is congruent with the degree of spiritual knowledge (ma'arifah)
they attain.''


For further reading on this, see:-
Ibn Ajiba's 'Al-Bahr al-Madid Fi Tafsir al-Qur'an al-Majid.'