I need to exit my xsl:for-each tag when I'm reaching a value. Example:

<xsl:for-each select="Person/Age">
    <xsl:if test=".='30'>
       ...
       <!-- Here I need to exit xsl:for-each -->
    </xsl:if>
</xsl:for-each>

You can put it inside the Xpath-Expression:
<xsl:for-each select="Person/Age[condition]">