Is there another saying with similar meaning to 'don't judge a book by it's cover'?
552112
It's what's on the inside that counts.\n\nDon't judge a book by its cover.\n\nAll that glitters isn't gold.\n\nAppearances are deceiving.\n\nLooks can be deceiving.\n\nGood things come in small packages. (you wouldn't expect it)\n\nLook with your eyes, judge with your soul.\n\nLook deep before you leap (to any conclusions)
914180
I have seen it used, but cannot find it in any dictionary.  It seems to be used "as in a liberal sense" or using prudence in a poetic license context.
533827
Unfortunately, many people use outward appearances as the measure of a person, and fail to look for the inner strenghts and beauty.  Our society has become one that has the luxury and superficiality that places great emphasis on outward appearances - consider the number of people with eating disorders, the starvation diets of models, the trend toward believeing that size 2 is normal, the number of people who get cosmetic surgery, the people working out in gyms to a level far beyond anything necessary for health, etc.  \n\nWhy would anyone think it odd that many people judge books by their covers?  People judge books by their covers because our society encourages and supports and fosters and approves that philosophy.
128697
"Ignorance is a bliss"\n\n"It's alright to gaze at the forever continuing sky, but\nYou can't just look look at the blue sky forever"
103466
1. The story is true.\n2. It describes not entertains.\n3. If it is a library book, it has a number rather than all  letters.
475065
Don't Ask, Don't Tell.\n\nYou violated the first. I won't violate the 2nd!
920631
"Flatter me, and I may not believe you.\nCriticize me, and I may not like you.\nIgnore me, and I may not forgive you.\nEncourage me, and I will not forget you."\n   -William Arthur Ward
53082
Cave ab homine unius libri. \nBeware the man of one book. \nAnonymous Latin saying, quoted by Isaac Disraeli in Curiosities of Literature, 1793
780852
It could be this one:\n\n"For only the truth which edifies is truth for you."
130999
"Never Settle for less but, remember... having more is not always important"\n\nAuthor : ME
1142342
"Before you decide to critize someone walk a mile in their shoes. Then when you critize them you are a mile away and you have their shoes"\n-sisterhood of the traveling pants (book 3 i think)\nIt's hilarious!!!
1080960
Yes, they are judging others, and their own book tells them not to.
312141
They try to judge a book by its cover. Just be yourself and let God be the judge.
309549
i have never heard of that expression.  i believe it may be a combination of the sayings \n"heaven forbid" (i hope it does not happen) and \n"perish the thought" (don't even think about it).  \nwhoever used that expression probably meant to use one of those sayings.  they are similar in meaning.
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Proverbs 17:10\n\n"A rebuke impresses a man of discernment more than a hundred lashes a fool."\n\n\nI know its' not exactly what you're looking for, but that's as close as I could find.
754108
If he said keep your nose in the books like prego suggests, it means don't neglect your studies.\n\nIf he said keeping the books, it means keep track of team stats, schedules, etc.
1081122
The Latin equivalent of your phrase is "Don't be willing to trust anyone ". According to the sense required, there are a few options.\n\nNoli cuiquam confidere ( rely on,have confidence in)\n\nNoli cuiquam credere (believe)\n\nNoli fidem cuiquam habere (have trust in the word of..)