I want to put a condition that text field only accept Hebrew charecter,

You can use the code() function to split a string into a list of numbers representing the Unicode number of the character, then confirm for all numbers they are greater than one value and less than the other (like the beginning and end of the Hebrew code blocks).

You may want to confirm in the unicode standard that you don't have a separate block for special Hebrew characters and punctuation.  I find that Unicode usually has 2 blocks for popular languages, the rarer symbols being grouped together further down the list.  I don't know if you'll need an additional block for Hebrew numbers.  I know that numerals in Arabic got it's own block.

True enough, you're going to need to account for both Hebrew block starting at  #0590 (that's hexadecimal) and the Hebrew Presentation Forms block starting at #FB00 (hexadecimal)  Go to unicode.org.

You can use the code() function to split a string into a list of numbers representing the Unicode number of the character, then confirm for all numbers they are greater than one value and less than the other (like the beginning and end of the Hebrew code blocks).

You may want to confirm in the unicode standard that you don't have a separate block for special Hebrew characters and punctuation.  I find that Unicode usually has 2 blocks for popular languages, the rarer symbols being grouped together further down the list.  I don't know if you'll need an additional block for Hebrew numbers.  I know that numerals in Arabic got it's own block.

True enough, you're going to need to account for both Hebrew block starting at  #0590 (that's hexadecimal) and the Hebrew Presentation Forms block starting at #FB00 (hexadecimal)  Go to unicode.org.