Shoftim

After the Torah warns us not to look into the future through sorcerers or black magic, it says תמים תהיה עם ה' אלקיך one should be complete with 'ה
Rashi explains that to mean that one shouldn't go after the fortune tellers to see the future, rather trust in what 'ה has in store for you & whatever happens, a person should accept wholeheartedly & then will be together with 'ה.

The אור החיים explains it a little differently & says that the only reason one would look to the future is to see what's in store for him. If he's not happy he'll try to change or fix whatever he feels is missing. The Torah tells us, תמים תהיה עם ה' אלקיך that if one will wholeheartedly trust 'ה they would not feel as if the were missing anything. As for their worries, even if the future would show something bad, it's not a definite. Like we saw by אברהם אבינו, even though the future said he wouldn't be able to have children, he who wholeheartedly walked with 'ה, did have children. So if one trusts 'ה there's no reason to look to the future.

The אור החיים's approach makes sense that we shouldn't look to the future & try to change it for 'ה knows best. However, what's Rashi trying to tell us when according to Rashi you're not trying to change anything, rather you're looking to the future to see if things will work out so you don't have to stress as much. Is that so wrong?

The עלינו לשבח opens our eyes to what Rashi is teaching us here, & says that everyone who thinks into their life can certainly look back & realize that it pays to wholeheartedly trust in 'ה, not look to fortune tellers. Rather to happily accept whatever 'ה gives and trust that it's for the good for in the end each one of us can bring proof by our own experiences that 'ה was two steps ahead. We know He only wants to do what's good for us. Therefore the best approach to life is to cast all your burdens on 'ה , to rely on Him wholeheartedly, & not try to foresee what's going to happen by going to fortune tellers.

He explains this with a parable. There was a traveler walking with a big bag over his shoulder, trudging down the road, when suddenly the skies open up & the rains relentlessly come down. he looks out hoping for carriage to come by. Suddenly he sees a fine carriage coming & he waves it down. The wealthy man stops for him & invites him onto the carriage. The traveler gratefully accepts & sits down in the carriage with his soaked bag on his lap.

The wealthy man looks over at him & says, why are you holding your heavy wet bag on your lap? Just put it on the floor of the carriage. The traveler says, you were kind enough to give me a ride & refuge from the rain; I don't want to trouble you anymore so I'll just hold my bag. The man looks at him incredulously & says, I'm carrying you & your bag anyway. It makes no difference if you relieve yourself of the burden; for me it's all the same.

As we laugh at the foolishness of the traveler, think - aren't we doing the same thing? Why do we carry around our "pekelach", always looking for an angle on how to somehow lighten the load, when we could just cast out burdens on 'ה? He's taking care of us anyway & controlling what happens, so why won't we relieve ourselves of the burden & cast it all on Him?!

This is what Rashi means. Don't look to the future, don't look for reassurance, rather wholeheartedly accept whatever you get, for if we don't worry & cast our "pekelach" on 'ה, then we are assured that whatever we're getting is what's best & there's no reason to worry.
Let us all cast our burdens aside & let 'ה do the worrying for us!