odoo/addons/sale/stock_view.xml

<?xml version="1.0" encoding="utf-8"?>
<openerp>
    <data>
        <record id="stock_picking_inherit_sale" model="ir.ui.view">
            <field name="name">stock.picking.form</field>
            <field name="model">stock.picking</field>
            <field name="type">form</field>
            <field name="inherit_id" ref="stock.view_picking_form"/>
            <field name="arch" type="xml">
                <field name="auto_picking" position="after">
                    <field name="sale_id"/>
                </field>
            </field>
        </record>
        
        <record id="stock_move_sale" model="ir.ui.view">
            <field name="name">stock.move.form</field>
            <field name="model">stock.move</field>
            <field name="type">form</field>
            <field name="inherit_id" ref="stock.view_move_form"/>
            <field name="arch" type="xml">
                 <xpath expr="/form/group/field[@name='tracking_id']"  position="before">
                    <field name="sale_line_id" colspan="2"/>
                </xpath>
            </field>
        </record>        
        <!-- Adding Sale Order Reference to outgoing picking -->
        
        <record id="stock_picking_out_inherit_sale" model="ir.ui.view">
            <field name="name">Outgoing picking Inherited</field>
            <field name="model">stock.picking</field>
            <field name="type">form</field>
            <field name="inherit_id" ref="stock.view_picking_out_form"/>
            <field name="arch" type="xml">
                <field name="move_type" position="after">
                    <field name="sale_id"/>
                </field>
            </field>
        </record>

    </data>
</openerp>