"rest completely" is correct and can be used in written English.
You can use it to indicate that someone needs to rest in order to regain their energy or to be able to do something. For example: "After a long day at work, I'm exhausted and need to rest completely before my next shift."
At first I had to rest completely.
"I'm sure if I told Coach I wanted to rest completely, he'd let me do that, too".
Bankia, however, issued a statement Thursday that said that "depositors can rest completely assured about the safety of the savings that they have entrusted to the entity".
He will rest completely for at least three days and arrive at the Yankees' complex in Tampa, Fla., as early as Sunday to continue his rehabilitation.
"We thought I should take the day off, rest completely and reduce the inflammation," said Feick, who has nearly finished his recovery from surgery in October.
He is still struggling and his pledge to rest completely when the season is over suggests he is prepared to play through the pain.
Mohamed Salah was rested completely as he receives treatment on a groin injury that is not expected to rule him out against City.
Giving workers enforceable rights will speed development, not delay it.Brendan BarberGeneral secretaryTrades Union CongressLondonGas for landSIR – The solution to Chile's energy problems rests completely within its control ("Praying for rain", May 19th).
Just months earlier, he and another researcher had revealed a study published by Science in 2014 as likely resting completely on fake data.
Just months earlier, he and Joshua Kalla, political scientists now at Stanford University in Palo Alto, California, and the University of California (UC), Berkeley, respectively, had revealed a study published by Science in 2014 as likely resting completely on fake data.
I told Zoey Deutch, "Young womanhood rests completely on your shoulders".
