Return Multiple Rows In Message Text

Hello. I have a problem in form personalization.
I wanna return multiple rows in message text.
Below is my code :
='Order Number ' || (select  distinct
    oha.order_number
from
    oe_order_headers_all oha,
    oe_order_lines_all oln,
    oe_transaction_types_all ota,
    wsh_delivery_details wdd,
    wsh_new_deliveries wnd,
    wsh_delivery_assignments_v wda
where
    oha.header_id = oln.header_id
    and oha.order_type_id = ota.transaction_type_id
    and wdd.source_header_id = oha.header_id
    and wdd.source_line_id = oln.line_id
    and wdd.delivery_detail_id = wda.delivery_detail_id 
    and wda.delivery_id = wnd.delivery_id