What is the authenticity of the saying "If you are pleased with your deeds, then know that Allah is not pleased with you"?

Sheikh: what? Questioner: If you are pleased with your deeds, then know that Allah is not pleased with you! Sheikh: I don’t know what that is? What is the evidence for such a statement? (In contrast) the believer is (supposed to be) pleased. “Say: "In the Bounty of Allâh, and in His Mercy (i.e. Islâm and the Qur’ân); - therein let them rejoice."“ (10:58). In this Ayah, the bounty of Allah refers to Islam, and His mercy refers to the Qur'an. So, being pleased with Islam and with the Qur'an is something good. Yes.