The letter was written after Van Gogh had heard from Gauguin that he was coming to Arles on 20 October. We have assumed that Van Gogh replied immediately otherwise there would not have been time for the letter to reach Gauguin before he set out. Since it is unlikely that Vincent had received Gauguin’s letter on 16 October – if he had, he would have told Theo about it when he wrote to him that evening (
letter 705) – we have dated this letter Wednesday, 17 October 1888.
Letter 707 was written the same day; it is not possible to tell which of the two was written first.