C# - ExecuteReader: CommandText property has not been initialized

public DataTable GetData()
    {
        DataTable Dt = new DataTable();

        using (System.Data.SqlClient.SqlConnection conn = new System.Data.SqlClient.SqlConnection())
        {
            conn.ConnectionString = System.Configuration.ConfigurationManager
                    .ConnectionStrings["BTSOConnectionString"].ConnectionString;
            using (System.Data.SqlClient.SqlCommand cmd = new System.Data.SqlClient.SqlCommand())
            {
                cmd.CommandText = DTSql;
                cmd.CommandType = CommandType.Text;
                cmd.Connection = conn;
                conn.Open();
                using (SqlDataAdapter da = new SqlDataAdapter())
                {
                    da.SelectCommand = cmd;
                    da.Fill(Dt);
                }
                conn.Close();
                conn.Dispose();
            }
        }
        return Dt;
    }

da.Fill(Dt);