John Trapp on Isaiah 66:17

Ver. 17. In the gardens] Where theſe Idolaters had ſet up Altars, offered ſacrifices,Donec me flumine vivo. Abluero. Virg. Qui noctem in flumine purgas: Perſ. i. e. nocturnam Venerem. and had their ponds, wherein when they were about to ſacrifice, heathen-like, they waſhed and purified themſelves one after another, and not together, which they held to be the beſt way of purifying. This they did alſo not apart and in private, but in the midſt, ut hoc modo oculos in nudis lavantium, praeſertim muliercularum, corporibus paſcerent, that they might feed their eyes with the ſight of thoſe parts which nature would have hid: for your Pagan ſuperſtitions were oft-times contrary to natural honeſty.

Behind one tree in the midſt] Or as others render it after, or behind Ahad, which was the name of a Syrian Idol,Saturnal. lib. 1. cap. 23. repreſenting the Sun, as Macrobius telleth us, calling him Adad.