Restrict acceess of a page in backend

How can I restrict editing of a page from backend only to a specific user?

I tried a few plugins but I thought doing it without plugins would be the way to go for me.

What measures I can take to solve this?

Solutions Collecting From Web of "Restrict acceess of a page in backend"

This can be done in two steps. First, add a hook to the page /wp-admin/edit.php?post_type=page to remove the desired page from appearing to other users. And another hook to redirect non-authorized users from trying to access the page directly /wp-admin/post.php?post=ID&action=edit.

Here, the post type is page, but it can be changed to any other. Make the adjustments indicated in the comments:

/**
 * Adjust the following:
 * post_type
 * User ID
 * Post ID
 */

add_action( 'load-edit.php', 'load_custom_filter_wpse_94387' );
add_action( 'load-post.php', 'block_page_access_wpse_94387' );

/**
 * Executed only in /wp-admin/edit.php
 *
 * Checks current post type and bail if not correct
 */
function load_custom_filter_wpse_94387()
{
    global $typenow;

    // Not the correct post type, do nothing
    if( 'page' != $typenow ) // <--- adjust
        return;

    add_filter( 'posts_where' , 'posts_where_wpse_94387' );
}

/**
 * If not authorized user, remove page from listing
 */
function posts_where_wpse_94387( $where ) 
{
    $current_user = wp_get_current_user();

    if ( 2 == $current_user->ID ) // <--- adjust
        return $where;

    $where .= ' AND ID != 119'; // <--- adjust
    return $where;
}

/**
 * Check if unauthorized user is trying to access restricted page
 */
function block_page_access_wpse_94387()
{
    // Check for post=119, if it is not this one, do nothing
    if( !isset( $_GET['post'] ) || '119' != $_GET['post'] ) // <--- adjust
        return;

    // Check for user, if allowed user, do nothing
    $current_user = wp_get_current_user();  
    if ( 2 == $current_user->ID ) // <--- adjust
        return;

    // Invalid attempt to edit the page, redirect
    wp_redirect( admin_url( 'edit.php?post_type=page' ) );
    exit();
}

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