Call procedure after some time

I would like to execute stored procedure after some time from now.
So, i have created queue and service:

CREATE QUEUE [dbo].[StartSAQueue] WITH STATUS = ON , RETENTION = OFF , ACTIVATION (  STATUS = ON , PROCEDURE_NAME = [dbo].[p_test_queue] , MAX_QUEUE_READERS = 1 , EXECUTE AS N'dbo'  ), POISON_MESSAGE_HANDLING (STATUS = ON) 

CREATE SERVICE [SAService]  ON QUEUE [dbo].[StartSAQueue] 
CREATE PROCEDURE dbo.p_test_queue
AS
DECLARE @Handle UNIQUEIDENTIFIER, @MessageType SYSNAME, @message NVARCHAR(255), @stevec INT;
RECEIVE TOP (1) @Handle = conversation_handle, @message=message_body FROM dbo.StartSAQueue;

IF @Handle IS NOT NULL
BEGIN  
END CONVERSATION @Handle;
INSERT INTO test.[dbo].[testQueue]([message]) VALUES(@message)
END

Now i start conversation:

DECLARE @DialogHandle UNIQUEIDENTIFIER;
DECLARE @RequestMessage XML;

BEGIN dialog CONVERSATION @DialogHandle FROM SERVICE [SAService] TO SERVICE N'SAService', 'current database' WITH ENCRYPTION = OFF;

SET @RequestMessage = N'<Request><SA>58</SA></Request>';

SEND ON CONVERSATION @DialogHandle(@RequestMessage);

It works.
Now i would like to execute this procedure after 10 minutes:

BEGIN CONVERSATION TIMER(@DialogHandle) TIMEOUT = 600;

It works. But how can i add message to this conversation? If I try this, it raises error:

BEGIN CONVERSATION TIMER(@DialogHandle(@RequestMessage)) TIMEOUT = 600;