'Every Green Tree' in the Bible

"For of old time I have broken your yoke, and burst your bonds; and you said, 'I will not serve;' for on every high hill and under every green tree you bowed yourself, playing the prostitute.

Moreover, the LORD said to me in the days of Josiah the king, "Have you seen that which backsliding Israel has done? She has gone up on every high mountain and under every green tree, and there has played the prostitute.

Only acknowledge your iniquity, that you have transgressed against the LORD your God, and have scattered your ways to the strangers under every green tree, and you have not obeyed my voice,'" says the LORD.