What is commonly called the golden rule is stated by Jesus in Matthew 7:12:
In everything, treat others as you would want them to treat you, for this fulfills the law and the prophets. (NET)
Commentators often notice that the golden rule appears in extra-biblical literature, but often in negative form.
For example, Ben Witherington states:
Jesus was by no means the first or only person to come up with a version of the Golden Rule. There is the famous saying of Rabbi Hillel, for example: “What is hateful to you, do not do to your neighbor: that is the whole Torah, while the rest is commentary on it; go and learn” (b. Sabb. 31a cf. Tob 4.15; 2 En. 61.1-2). It is worth pointing out that Jesus insists on a positive formulation of the maxim, where as other forms of it, both Jewish and Greco-Roman (cf. Isocrates Nic. 61; Herodotus 3.142), tend to be negative.
Are there any positive statements of this principle to be found in extra-biblical literature? (Excluding, of course, Christian literature or later literature influenced by Christianity)