Vayeira

When on the behest of Sara, Avraham sends Hagar & Yishmael away, Yishmael gets sick & finishes all the water they had in the middle of the journey. Hagar, fearing that her child would die, is overcome with feelings of helplessness and throws Yishmael under a nearby tree so as not to see him die. She then sits down & begins to cry.

Hashem hears the cries of the boy & sends an angel down to Hagar. The angel tells her to pick up the boy & then ויפקח אלקים את עיניה  Hashem opened her eyes ותרא באר מים ותלך ותמלא את החמת מים & she saw a well of water. She went, filled the skin with water ותשק את הנער & gave the boy to drink.
Interestingly enough, the Midrash says הדא אמרת מחוסרת אמנה היתה from here we say that she was lacking in her faith , for, by filling up the flask with more than she needed at that moment, she showed that her trust in Hashem was lacking.

Asks הגרי"ל חסמן, this Midrash is very puzzling. This is a woman who is alone in the forest with a sick child with no water, who miraculously comes upon a well. Shouldn't we expect her to take for later?
He answers this question with a parable. There was a man who was invited to travel with the king in his entourage with the understanding that the king will provide all that's needed for the journey. If this man would bring his own food & drink, it would be a personal affront to the king.  

We are all riding in Hashem's chariot. Therefore, every time we worry, it’s a personal affront to Hashem who's taking care of us. This is what the claim against Hagar was. After she had seen the great miracle where a well was created just for her, she should have realized that Hashem would be with her & provide for her as needed. Just as she had water now when needed, she would have later too. There was no reason to take extra.

This says ר' אליהו לאפיין  shows us that each person is provided for & judged based on one’s own level of faith. Since we know that one should not rely on miracles, how then could we have a claim against Hagar for taking more. She also shouldn't rely on miracles. He answers that a woman like Hagar who left her father’s home, the home of a king, to attach herself to Avraham should be held to a higher standard. A woman who was accustomed to speak to angels & whom the angel even informed that her son would be made into a great nation, was a woman who was riding in Hashem’s chariot. For her, this was a lack of faith.  
To what extent are we not to worry?

The gemara in Megila says the rabbis didn't understand the verse השלך על ה' יהבך , cast your burdens on Hashem, until one time they were traveling & the Arab camel driver said to them, cast your baggage on the camel. That's when they understood what the extent of bitachon is supposed to be. Just as when you cast your baggage on the camel, you don't feel it anymore, so too, when you cast your burden on Hashem, it has to be that you won't feel it or worry about it because you gave it over to Hashem to carry for you.

As the Midrash says, when a big fish chases a smaller fish as prey, it never catches it. Had it caught and swallowed it from behind, then the fins of the small fish would choke the big fish on the way down. Hashem, too, in his infinite wisdom, made it so that the small fish just swims headfirst, straight into the mouth of the big one. In this way, the fins just fold down without causing any harm. Turns out the big fish chases his food but doesn't catch it for it would just hurt him. Then his food just comes from somewhere else & comes straight to him.

How many times do we see this in business? We go after one deal. When it doesn't work out, we think all is lost until, from out of nowhere, a better, easier one develops. This is what we have to appreciate from here. We have to trust that we’re riding in Hashem’s chariot. If we put our baggage on him, we don't have to worry. No matter how things look, we are not in control & Hashem will take care of us!